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Antenna Yak52

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pa3arw(at)euronet.nl
Guest

Posted: Wed Jul 04, 2012 1:14 pm Post subject: Antenna Yak52

Guys,

 

 Has anybody removed or swapped the antenna on a Yak52??

 Mine is broken and completely corroded so needs to be replaced.

 If I want to remove it, it means damaging the paint and I was wondering if only the radiator could be removed rather than the whole assembly??

 Pictures or drawings would be appreciated!

 

 Thanks!

 

 Hans O.

 RA3326K

 Netherlands       [quote][b]

mark.bitterlich(at)navy.m
Guest

Posted: Wed Jul 04, 2012 2:49 pm Post subject: Antenna Yak52

The stock Russian antenna has a small matching network inside.  If you want to go to the effort, the radiator can be replaced.  It is actually a threaded tapered rod.  The best bet would be to ask around and see if you can find an old one that someone removed that you can just thread in and be done. 

 

Personally, I took the antenna off, then drilled the original plate for a more modern antenna and mounted it on the same plate.  Doing it this way you really should not notice any damage to your paint?  In any case, you would have to slice around the mounting plate so you could remove it.  I think I have one that I could take pictures of for you, but it would take a few days since I am currently not home.  If anyone else has pictures, I am sure that would help you much better than this email.  

 

Mark

 



________________________________



From: owner-yak-list-server(at)matronics.com on behalf of Hans Oortman

Sent: Wed 7/4/2012 5:11 PM

To: yak-list

Subject: Antenna Yak52

Guys,



Has anybody removed or swapped the antenna on a Yak52??

Mine is broken and completely corroded so needs to be replaced.

If I want to remove it, it means damaging the paint and I was wondering if only the radiator could be removed rather than the whole assembly??

Pictures or drawings would be appreciated!



Thanks!



Hans O.

RA3326K

Netherlands

pa3arw(at)euronet.nl
Guest

Posted: Fri Jul 06, 2012 12:27 am Post subject: Antenna Yak52

Thanks Mark....I can not reach the guts of the antenna myself but found a

small guy who can.... Jan probably has still an antenna, so I'll wait what

he can find.



Buy the way: I hate matching networks, the only thing it does is match the

impedance but pulls down the efficiency....



I'll keep you posted!



Hans

Op 05-07-12 00:42, Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E

<mark.bitterlich(at)navy.mil> schreef:



 	  Quote: 	
		   

 MALS-14 64E" <mark.bitterlich(at)navy.mil>

 

 The stock Russian antenna has a small matching network inside.  If you want to

 go to the effort, the radiator can be replaced.  It is actually a threaded

 tapered rod.  The best bet would be to ask around and see if you can find an

 old one that someone removed that you can just thread in and be done.

  

 Personally, I took the antenna off, then drilled the original plate for a more

 modern antenna and mounted it on the same plate.  Doing it this way you really

 should not notice any damage to your paint?  In any case, you would have to

 slice around the mounting plate so you could remove it.  I think I have one

 that I could take pictures of for you, but it would take a few days since I am

 currently not home.  If anyone else has pictures, I am sure that would help

 you much better than this email.

  

 Mark

  

 

 ________________________________

 

 From: owner-yak-list-server(at)matronics.com on behalf of Hans Oortman

 Sent: Wed 7/4/2012 5:11 PM

 To: yak-list

 Subject: Antenna Yak52

 

 

 Guys,

 

 Has anybody removed or swapped the antenna on a Yak52??

 Mine is broken and completely corroded so needs to be replaced.

 If I want to remove it, it means damaging the paint and I was wondering if

 only the radiator could be removed rather than the whole assembly??

 Pictures or drawings would be appreciated!

 

 Thanks!

 

 Hans O.

 RA3326K

 Netherlands

mark.bitterlich(at)navy.m
Guest

Posted: Fri Jul 06, 2012 7:49 am Post subject: Antenna Yak52

Concur, which is why I mounted a new antenna on there and took the old

one OFF!   



Mark

--

mark.bitterlich(at)navy.m
Guest

Posted: Fri Jul 06, 2012 10:20 am Post subject: Antenna Yak52

I might point out that physics is a problem here as well. 



One piece of metal as an antenna cannot be made to provide a

characteristic impedance of 50 ohms from 118 to 136 MHz.  You pretty

much have to come up a way around that issue.   



Mark



p.s. Go ahead Brian.  

--

k7wx

Joined: 24 May 2010
Posts: 117

Posted: Fri Jul 06, 2012 10:49 am Post subject: Antenna Yak52

Mark,



As you know, a straight 1/4 wavelength vertical radiator has a relatively narrow bandwidth. The SWR will be good at 1/4 and possibly 5/8 wavelength, but rises quickly after that. There is no way to make a single element vertical antenna efficient from 118 to 136 MHz. It can be tuned at the center frequency and we just have to accept the high SWR towards the ends of the band. Also, the anodized aluminum panels on the CJ do not always conduct well between each one. 



The other weak point in aviation communications is the coax and the BNC connectors. RG-58 is pretty lossy at 120 MHz and a poorly fashioned BNC connector easily has a 1 to 2 dB insertion loss. For every 3 dB of loss the signal strength is cut by 50%, outgoing and incoming. So... a non-resonant antenna with a shaky counterpoise, two low quality, crimped BNC connectors on RG-58 coax and even the best radio may seem less than adequate from 20 miles out. 



The good news is that just about everything we do is line of sight and at these frequencies it doesn't take much radiated power to maintain a reasonable signal strength. 



Warren



On Jul 6, 2012, at 11:17 AM, Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E wrote:



[quote] 

 

 I might point out that physics is a problem here as well. 

 

 One piece of metal as an antenna cannot be made to provide a

 characteristic impedance of 50 ohms from 118 to 136 MHz.  You pretty

 much have to come up a way around that issue.   

 

 Mark

 

 p.s. Go ahead Brian.  

 

 

 --

mark.bitterlich(at)navy.m
Guest

Posted: Sat Jul 07, 2012 12:09 pm Post subject: Antenna Yak52

Roger that Warren.  As you know, the feedpoint impedance of a 1/4 wave radiator is actually about 36 ohms, giving a best match of about 1.5 to 1 VSWR.  Whereas in order to feed a 5/8 wave design, you try to make the 5/8 wave antenna appear to be about 3/4 wavelength which will establish a pretty good match and also give the ideal low angle of radiation that can be gained with the actual 5/8 wave length of the antenna.  This is typically done by using a base loading coil.  Typical aircraft designs avoid 5/8 wavelength due to the compressed pattern that is good for fixed stations, but bad for a moving platform with pitch and roll.  

 

Only really cheap avionics shops use RG-58 for the reasons you specified. A much better alternative and what aircraft owners should specifically ask for is RG-142 B/U which is a teflon dielectric silver tinned double shielded coax that has a higher velocity factor than standard coax and thus lower loss.  This coax is good for short runs even at 1.5 GHz, such as a GPS antenna for example.  If more flexibility is needed in the coax (the teflon is kind of stiff), I recommend RG-223, which is the same as RG-142, except it has a poly dielectric rather than teflon.  

 

If you are a warbird with LONG coax runs, I recommend RG-393/U which is the roughly 0.5" variety of PTFE dielectric coax.  It has even lower loss (large center conductor) is also silver tinned.  Again if stiffness is a factor, the alternative is RG-214.  

 

I recommend avoiding crimp on connectors of ANY type.  Avionics shops love them because they are easy and FAST to put on.  Putting a standard BNC or TNC connector takes time, and a little bit of soldering skill.  That said, I never ever use crimp-on's.  

 

But just for giggles let's compare .......   A 20 foot run of RG-142 at 130 Mhz will give a loss of about 0.9 dB    But with tongue in cheek, let me also submit that a 20 foot run of RG-58 will have a loss of 1.0 dB, thus a difference of only 0.1 dB.    At 1500 Mhz, basically GPS range, you are looking at a 20 foot run of RG-58 having 3.8 dB of loss and RG-142 3.2 dB, a difference of 0.6 dB 

 

So a true nit-picker would submit that the higher cost of RG-142 is not worth it ..... but I submit it is much more rugged, and will last MUCH LONGER compared to anything else.  

 

Of course, the real advantage of RG-393 is that it will handle 10 Kw of average power at 20 Mhz... needed when you are running a 3CX3000A7 with 7000 volts on the plate.  

 

Take care Warren, 

 

Mark

WA3JPY

 

 

 

 

________________________________



From: owner-yak-list-server(at)matronics.com on behalf of Warren Hill

Sent: Fri 7/6/2012 2:47 PM

To: yak-list(at)matronics.com

Subject: Re: Antenna Yak52






Mark,



As you know, a straight 1/4 wavelength vertical radiator has a relatively narrow bandwidth. The SWR will be good at 1/4 and possibly 5/8 wavelength, but rises quickly after that. There is no way to make a single element vertical antenna efficient from 118 to 136 MHz. It can be tuned at the center frequency and we just have to accept the high SWR towards the ends of the band. Also, the anodized aluminum panels on the CJ do not always conduct well between each one.



The other weak point in aviation communications is the coax and the BNC connectors. RG-58 is pretty lossy at 120 MHz and a poorly fashioned BNC connector easily has a 1 to 2 dB insertion loss. For every 3 dB of loss the signal strength is cut by 50%, outgoing and incoming. So... a non-resonant antenna with a shaky counterpoise, two low quality, crimped BNC connectors on RG-58 coax and even the best radio may seem less than adequate from 20 miles out.



The good news is that just about everything we do is line of sight and at these frequencies it doesn't take much radiated power to maintain a reasonable signal strength.



Warren



On Jul 6, 2012, at 11:17 AM, Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E wrote:



[quote] 



 I might point out that physics is a problem here as well.



 One piece of metal as an antenna cannot be made to provide a

 characteristic impedance of 50 ohms from 118 to 136 MHz.  You pretty

 much have to come up a way around that issue.  



 Mark



 p.s. Go ahead Brian. 

 --

wlannon(at)shaw.ca
Guest

Posted: Sat Jul 07, 2012 7:38 pm Post subject: Antenna Yak52

Hi Mark;



Just finishing up the avionics installations in my CJ project.   I used Mil. 

Spec. M17/128-RG400  for all units.   2 comms,  TXPDR and GPS.   Had 

intended to use RG 142 for the GPS but the local avionics shop (who have a 

very good reputation) said the RG400 would be fine.   It's only a 3 ft. run 

so I assume either would be OK.   Both are silver plated central conductor 

and double silver plated shields.



Do you see any problem with that?



Many thanks;



Walt



--

wlannon(at)shaw.ca
Guest

Posted: Sat Jul 07, 2012 7:49 pm Post subject: Antenna Yak52

Mark;



Forgot to mention that due to questionable antennae and coax placement (not 

much room in the CJ) I also installed a 1.????? GHZ notch filter at each 

comm.  Can't remember the number.  Any comments?



Cheers;

Walt



--

brian(at)lloyd.com
Guest

Posted: Sun Jul 08, 2012 12:27 am Post subject: Antenna Yak52

On Sat, Jul 7, 2012 at 11:35 PM, Walter Lannon <wlannon(at)shaw.ca (wlannon(at)shaw.ca)> wrote:

 	  Quote: 	
		   --> Yak-List message posted by: "Walter Lannon" <wlannon(at)shaw.ca (wlannon(at)shaw.ca)>

 

 Hi Mark;

 

 Just finishing up the avionics installations in my CJ project.   I used Mil. Spec. M17/128-RG400  for all units.   2 comms,  TXPDR and GPS.   Had intended to use RG 142 for the GPS but the local avionics shop (who have a very good reputation) said the RG400 would be fine.   It's only a 3 ft. run so I assume either would be OK.   Both are silver plated central conductor and double silver plated shields.

  

 Do you see any problem with that?

	




Nope. RG400 is functionally equivalent to RG-142. The teflon dielectric and double-shield, silver-plated braid are the keys. And Mark is right that these coax cables last a lot longer than cheaper RG-58. If you are going to spend several thousands of dollars on your radios, trying to save $50 on your coax feed-line is silly. 

 



The one thing I disagree with Mark on is the use of crimp-on connectors. I use crimp-on connectors for everything. Turns out that crimping makes a superior gas-tight connection which makes the connection last longer and be less subject to failure. Combine that with proper application of self-sealing (heat-activated adhesive inside) heat shrink tubing and you have a superior termination even to solder-on terminations. That it is easier and faster to do is just a plus. (You need a good ratcheting crimp tool with the proper dies tho'!) 

 



And, no, I am not looking for an argument. The information is available from the manufacturers of the connectors. They have done the testing and will provide the results if you are interested.

 



The key here is that you will have no trouble finding best standard practices in the industry. It is what good radio shops use. Good quality coax, e.g. RG400, properly terminated with crimp-on connectors, sealed with self-sealing heat-shrink, IS best standard practice. That is why good radio shops use this approach over and over again with good success. If it didn't work, they would be losing money on rework so would change their techniques.

 



One can argue antennas 'till the cows come home but mechanical issues tend to outweigh the electrical issues. Standard production aircraft antennas work just fine with standard production aircraft radios. Yes, you need to make sure that the base of the antenna makes good connection with the aircraft skin but that just means cleaning any paint or other coating from the skin around the bolt holes prior to mounting the antenna. I like to mount my antennas "wet" by applying zinc chromate to the skin around the bolt holes just before bolting the antenna down. The wet zinc chromate allows the metals to come together to form an electrical bond but then the zinc chromate dries to provide a corrosion barrier. 

 



This is not rocket science.



-- 

Brian Lloyd, WB6RQN/J79BPL

3191 Western Dr.

Cameron Park, CA 95682

brian(at)lloyd.com (brian(at)lloyd.com)

 +1.767.617.1365 (Dominica)

+1.916.877.5067 (USA)



  [quote][b]

mark.bitterlich(at)navy.m
Guest

Posted: Sun Jul 08, 2012 8:12 am Post subject: Antenna Yak52

Absolutely not.  RG-400 is just as good.  Tells me that your Avionics Shop knows what they are doing. 

 

Mark

 



________________________________



From: owner-yak-list-server(at)matronics.com on behalf of Walter Lannon

Sent: Sat 7/7/2012 11:35 PM

To: yak-list(at)matronics.com

Subject: Re: Antenna Yak52






Hi Mark;



Just finishing up the avionics installations in my CJ project.   I used Mil.

Spec. M17/128-RG400  for all units.   2 comms,  TXPDR and GPS.   Had

intended to use RG 142 for the GPS but the local avionics shop (who have a

very good reputation) said the RG400 would be fine.   It's only a 3 ft. run

so I assume either would be OK.   Both are silver plated central conductor

and double silver plated shields.



Do you see any problem with that?



Many thanks;



Walt



--

mark.bitterlich(at)navy.m
Guest

Posted: Sun Jul 08, 2012 9:08 am Post subject: Antenna Yak52

Hello Brian, 

 

I have been expecting your reply to be honest.  

 

First, ... Hey Walt, you're correct (and so is Brian) RG-400 is just fine

 

Brian, you are welcome to disagree with me.  There are many grades and types of crimp on connectors.   And obviously they would work, or there wouldn't be so many out there.  My personal bias is based on the 42 years of experience I have had with them on aircraft.  Some gas tight crimps that are out there, specifically the types I normally see on 20 Ghz Gore Line for example are indeed superior to anything else made.  These are typically factory assembled and are not repairable in the field.  If they are, you can only replace the end fitting, and not swage in a totally new connector to the transmission line itself.  In addition, keep in mind that I am talking to aircraft owners/pilots, who might want to repair their own aircraft.  

 

Typical crimp on connectors, are not gas tight.  In fact, there is special coax designations, or "MilSpec" if you will, that are specifically designated for gas tight crimps.  RG-142, 400, 214, 393, etc., are not gas tight transmission lines.  But yes,.. you could use gas tight crimps on them if you wanted.  What I am referring to is what I'll call  "The Standard Crimp on Connector".  If these are assembled and crimped on properly.... 

 

WAIT WAIT !!!!!  There is that sneaky "IF" word that just crept in.  The "IF" means that you have in your hands, the exact correct type of crimp tool, properly adjusted, and know how to us it ... if all that is true, you can create a good operational RF connector on the end of the transmission line.  But it is not gas tight, any more than a manually assembled connector.  You mention this yourself when you commented on a properly ratcheting crimp tool.  And in most cases, an aircraft owner/operator is not going to go out and purchase the best quality crimping tools and dies out there.  Avionics Shops might... maybe.  Not always. 

 

Yes, there is indeed a special connector, historically tracing it's roots back to the RayChem company, that has self sealing heat activated material inside.  Now we need the proper heat gun, ... or you can just wild ass guess it with a hot air gun, and in this case a seal is made, that is probably a tad superior to the rubber self split ring concept of the manually made connectors.  However, I mildly object to the term "gas tight" as that is a phrase normally reserved for connectors designed to be used on specific gas tight transmission lines.  However, given what we are talking about here, it really doesn't matter.  

 

Finally, we get to the heat shrink tubing that you mentioned putting on the outside of the coax line.  This is the most important thing you said ... in my opinion. Typical crimped connectors put a physical stress point on the coax line itself, causing premature failure right behind the connector.  Putting not only heat shrink, but the proper TYPE of heat shrink over that possible flex point, will improve the life of the crimp on connector.  But then, it will do the exact same thing on a manually assembled, soldered center pin connector.  So heat shrink installed on ANY connector is by and large "A GOOD THING".  

 

You mention that crimp on connectors with heat shrink backing "IS BEST STANDARD PRACTICE".   Well, I guess that depends on what standards you are referring to  Clearly they are best by your standards,  

 

You then said:  "That is why good radio shops use this approach over and over again with good success. If it didn't work, they would be losing money on rework so would change their techniques."   That is, in my opinion, flawed reasoning.  With the General Aviation Avionics Shops that I have experience with, if something works going out the door, and then you come back a year later with a damaged connector, they are not going to fix it for free because it did not last as long as you thought it should.  They will fix it exactly the same way again, and charge you for it.  Avionics shops are out to make money, and very few of them sacrifice their time to make a connector last longer.  I am well aware that using crimp on connectors is "standard practice" for most shops, but that does not make it the "best method", it makes it the fastest and cheapest method, and THAT is what they are looking for.  

 

AND... of all the connectors I have seen Avionics Shops put on, few if ANY put heat shrink on the back, and NONE have ever used a connector with internal heat activated sealant.  Those types cost too much.  

 

The reason I prefer the type I promoted Brian, is because I have been working with these types of connectors for 42 years on military aircraft, every single day.  It is true that crimp connectors can be made to last longer.  However, the manually soldered on types that I prefer, with heat shrink on the back, last longer than anything else.  

 

Antennas ... interesting that you brought that up.  The mechanical bond between aircraft skin and antenna is obviously critical for best performance.  A funded study was performed on this issue about 15 years ago by the Department of Defense,   This is a significant issue, especially for USN, and USMC aircraft as they operate in highly corrosive environments.  The result of this study is that now all USN and USMC aircraft use a very special conductive sealing method for all external antennas.  Give a Google look-up for: "AV-Dec" and read all about it there.  AV-Dec is NOT "best standard practice" by any means.  It is BEST POSSIBLE PRACTICE, and I've yet to see it used in General Aviation, except on my aircraft of course.  

 

You said: "This is not rocket science".   Correct, far from it.  Actually it is your and my OPINIONS being expressed on the YAK List.  Not even close to Rocket Science.  .    

 

Mark

 

p.s.  The short version:  "I think we'll agree to disagree on this one.  

 



________________________________



From: owner-yak-list-server(at)matronics.com on behalf of Brian Lloyd

Sent: Sun 7/8/2012 4:23 AM

To: yak-list(at)matronics.com

Subject: Re: Antenna Yak52

On Sat, Jul 7, 2012 at 11:35 PM, Walter Lannon <wlannon(at)shaw.ca> wrote:

	

	

	Hi Mark;

	

	Just finishing up the avionics installations in my CJ project.   I used Mil. Spec. M17/128-RG400  for all units.   2 comms,  TXPDR and GPS.   Had intended to use RG 142 for the GPS but the local avionics shop (who have a very good reputation) said the RG400 would be fine.   It's only a 3 ft. run so I assume either would be OK.   Both are silver plated central conductor and double silver plated shields.

	

	Do you see any problem with that?

	

Nope. RG400 is functionally equivalent to RG-142. The teflon dielectric and double-shield, silver-plated braid are the keys. And Mark is right that these coax cables last a lot longer than cheaper RG-58. If you are going to spend several thousands of dollars on your radios, trying to save $50 on your coax feed-line is silly. 



The one thing I disagree with Mark on is the use of crimp-on connectors. I use crimp-on connectors for everything. Turns out that crimping makes a superior gas-tight connection which makes the connection last longer and be less subject to failure. Combine that with proper application of self-sealing (heat-activated adhesive inside) heat shrink tubing and you have a superior termination even to solder-on terminations. That it is easier and faster to do is just a plus. (You need a good ratcheting crimp tool with the proper dies tho'!) 



And, no, I am not looking for an argument. The information is available from the manufacturers of the connectors. They have done the testing and will provide the results if you are interested.



The key here is that you will have no trouble finding best standard practices in the industry. It is what good radio shops use. Good quality coax, e.g. RG400, properly terminated with crimp-on connectors, sealed with self-sealing heat-shrink, IS best standard practice. That is why good radio shops use this approach over and over again with good success. If it didn't work, they would be losing money on rework so would change their techniques.



One can argue antennas 'till the cows come home but mechanical issues tend to outweigh the electrical issues. Standard production aircraft antennas work just fine with standard production aircraft radios. Yes, you need to make sure that the base of the antenna makes good connection with the aircraft skin but that just means cleaning any paint or other coating from the skin around the bolt holes prior to mounting the antenna. I like to mount my antennas "wet" by applying zinc chromate to the skin around the bolt holes just before bolting the antenna down. The wet zinc chromate allows the metals to come together to form an electrical bond but then the zinc chromate dries to provide a corrosion barrier. 



This is not rocket science.



-- 

Brian Lloyd, WB6RQN/J79BPL

3191 Western Dr.

Cameron Park, CA 95682

brian(at)lloyd.com

+1.767.617.1365 (Dominica)

+1.916.877.5067 (USA)

jan.mevis(at)informavia.b
Guest

Posted: Sun Jul 08, 2012 10:55 am Post subject: Antenna Yak52

I've crimped hundreds of BNC connectors on coax, back in the eighties when

twisted pair was not used yet for Ethernet. And it took a while before I

was reasonably proficient.



In those days we had to use the crimp tool just because of "production

speed".



I also have seen two radio's with their end amplification transistor blown

up because of a BNC connector, crimped on the coax, and became loose.



I prefer soldering but must also admit that I often take the crimp tool,

just because it's so easy to use. Soldering a BNC connector is not that

simple either, for the layman, isn't it?



Jan



 





On 08/07/12 19:05, "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E"

<mark.bitterlich(at)navy.mil> wrote:



 	  Quote: 	
		  

MALS-14 64E" <mark.bitterlich(at)navy.mil>



Hello Brian, 

 

I have been expecting your reply to be honest.

 

First, ... Hey Walt, you're correct (and so is Brian) RG-400 is just fine

 

Brian, you are welcome to disagree with me.  There are many grades and

types of crimp on connectors.   And obviously they would work, or there

wouldn't be so many out there.  My personal bias is based on the 42 years

of experience I have had with them on aircraft.  Some gas tight crimps

that are out there, specifically the types I normally see on 20 Ghz Gore

Line for example are indeed superior to anything else made.  These are

typically factory assembled and are not repairable in the field.  If they

are, you can only replace the end fitting, and not swage in a totally new

connector to the transmission line itself.  In addition, keep in mind

that I am talking to aircraft owners/pilots, who might want to repair

their own aircraft.

 

Typical crimp on connectors, are not gas tight.  In fact, there is

special coax designations, or "MilSpec" if you will, that are

specifically designated for gas tight crimps.  RG-142, 400, 214, 393,

etc., are not gas tight transmission lines.  But yes,.. you could use gas

tight crimps on them if you wanted.  What I am referring to is what I'll

call  "The Standard Crimp on Connector".  If these are assembled and

crimped on properly....

 

WAIT WAIT !!!!!  There is that sneaky "IF" word that just crept in.  The

"IF" means that you have in your hands, the exact correct type of crimp

tool, properly adjusted, and know how to us it ... if all that is true,

you can create a good operational RF connector on the end of the

transmission line.  But it is not gas tight, any more than a manually

assembled connector.  You mention this yourself when you commented on a

properly ratcheting crimp tool.  And in most cases, an aircraft

owner/operator is not going to go out and purchase the best quality

crimping tools and dies out there.  Avionics Shops might... maybe.  Not

always. 

 

Yes, there is indeed a special connector, historically tracing it's roots

back to the RayChem company, that has self sealing heat activated

material inside.  Now we need the proper heat gun, ... or you can just

wild ass guess it with a hot air gun, and in this case a seal is made,

that is probably a tad superior to the rubber self split ring concept of

the manually made connectors.  However, I mildly object to the term "gas

tight" as that is a phrase normally reserved for connectors designed to

be used on specific gas tight transmission lines.  However, given what we

are talking about here, it really doesn't matter.

 

Finally, we get to the heat shrink tubing that you mentioned putting on

the outside of the coax line.  This is the most important thing you said

... in my opinion. Typical crimped connectors put a physical stress point

on the coax line itself, causing premature failure right behind the

connector.  Putting not only heat shrink, but the proper TYPE of heat

shrink over that possible flex point, will improve the life of the crimp

on connector.  But then, it will do the exact same thing on a manually

assembled, soldered center pin connector.  So heat shrink installed on

ANY connector is by and large "A GOOD THING".

 

You mention that crimp on connectors with heat shrink backing "IS BEST

STANDARD PRACTICE".   Well, I guess that depends on what standards you

are referring to  Clearly they are best by your standards,

 

You then said:  "That is why good radio shops use this approach over and

over again with good success. If it didn't work, they would be losing

money on rework so would change their techniques."   That is, in my

opinion, flawed reasoning.  With the General Aviation Avionics Shops that

I have experience with, if something works going out the door, and then

you come back a year later with a damaged connector, they are not going

to fix it for free because it did not last as long as you thought it

should.  They will fix it exactly the same way again, and charge you for

it.  Avionics shops are out to make money, and very few of them sacrifice

their time to make a connector last longer.  I am well aware that using

crimp on connectors is "standard practice" for most shops, but that does

not make it the "best method", it makes it the fastest and cheapest

method, and THAT is what they are looking for.

 

AND... of all the connectors I have seen Avionics Shops put on, few if

ANY put heat shrink on the back, and NONE have ever used a connector with

internal heat activated sealant.  Those types cost too much.

 

The reason I prefer the type I promoted Brian, is because I have been

working with these types of connectors for 42 years on military aircraft,

every single day.  It is true that crimp connectors can be made to last

longer.  However, the manually soldered on types that I prefer, with heat

shrink on the back, last longer than anything else.

 

Antennas ... interesting that you brought that up.  The mechanical bond

between aircraft skin and antenna is obviously critical for best

performance.  A funded study was performed on this issue about 15 years

ago by the Department of Defense,   This is a significant issue,

especially for USN, and USMC aircraft as they operate in highly corrosive

environments.  The result of this study is that now all USN and USMC

aircraft use a very special conductive sealing method for all external

antennas.  Give a Google look-up for: "AV-Dec" and read all about it

there.  AV-Dec is NOT "best standard practice" by any means.  It is BEST

POSSIBLE PRACTICE, and I've yet to see it used in General Aviation,

except on my aircraft of course.

 

You said: "This is not rocket science".   Correct, far from it.  Actually

it is your and my OPINIONS being expressed on the YAK List.  Not even

close to Rocket Science.  .

 

Mark

 

p.s.  The short version:  "I think we'll agree to disagree on this one.

 



________________________________



From: owner-yak-list-server(at)matronics.com on behalf of Brian Lloyd

Sent: Sun 7/8/2012 4:23 AM

To: yak-list(at)matronics.com

Subject: Re: Antenna Yak52

On Sat, Jul 7, 2012 at 11:35 PM, Walter Lannon <wlannon(at)shaw.ca> wrote:

	

	

	Hi Mark;

	

	Just finishing up the avionics installations in my CJ project.   I used

Mil. Spec. M17/128-RG400  for all units.   2 comms,  TXPDR and GPS.   Had

intended to use RG 142 for the GPS but the local avionics shop (who have

a very good reputation) said the RG400 would be fine.   It's only a 3 ft.

run so I assume either would be OK.   Both are silver plated central

conductor and double silver plated shields.

	

	Do you see any problem with that?

	

Nope. RG400 is functionally equivalent to RG-142. The teflon dielectric

and double-shield, silver-plated braid are the keys. And Mark is right

that these coax cables last a lot longer than cheaper RG-58. If you are

going to spend several thousands of dollars on your radios, trying to

save $50 on your coax feed-line is silly.



The one thing I disagree with Mark on is the use of crimp-on connectors.

I use crimp-on connectors for everything. Turns out that crimping makes a

superior gas-tight connection which makes the connection last longer and

be less subject to failure. Combine that with proper application of

self-sealing (heat-activated adhesive inside) heat shrink tubing and you

have a superior termination even to solder-on terminations. That it is

easier and faster to do is just a plus. (You need a good ratcheting crimp

tool with the proper dies tho'!)



And, no, I am not looking for an argument. The information is available

from the manufacturers of the connectors. They have done the testing and

will provide the results if you are interested.



The key here is that you will have no trouble finding best standard

practices in the industry. It is what good radio shops use. Good quality

coax, e.g. RG400, properly terminated with crimp-on connectors, sealed

with self-sealing heat-shrink, IS best standard practice. That is why

good radio shops use this approach over and over again with good success.

If it didn't work, they would be losing money on rework so would change

their techniques.



One can argue antennas 'till the cows come home but mechanical issues

tend to outweigh the electrical issues. Standard production aircraft

antennas work just fine with standard production aircraft radios. Yes,

you need to make sure that the base of the antenna makes good connection

with the aircraft skin but that just means cleaning any paint or other

coating from the skin around the bolt holes prior to mounting the

antenna. I like to mount my antennas "wet" by applying zinc chromate to

the skin around the bolt holes just before bolting the antenna down. The

wet zinc chromate allows the metals to come together to form an

electrical bond but then the zinc chromate dries to provide a corrosion

barrier. 



This is not rocket science.



-- 

Brian Lloyd, WB6RQN/J79BPL

3191 Western Dr.

Cameron Park, CA 95682

brian(at)lloyd.com

+1.767.617.1365 (Dominica)

+1.916.877.5067 (USA)

mark.bitterlich(at)navy.m
Guest

Posted: Sun Jul 08, 2012 11:24 am Post subject: Antenna Yak52

Jan, I agree with you 100%.  

 

I was not being at all fair when making the comparison between these two types of connectors.  Specifically in that putting together a manually assembled connector requires experience and knowledge and is far from simple.  After manually unbraiding and then soldering the center conductor on way WAY too many N, HN, C, BNC, TNC connectors, which I can now do very well, I despise the amount of time it takes to do it.  

 

That said, on MY equipment, I choose the harder method, simply because I know if it is done right, it will work a LONG time without failure.  

 

And of those hundreds of crimped on BNC's ... how many did you put heatshrink on?  I'm going to guess "none".    

 

Both types of connectors require experience and technique.  The manually assembled connectors take longer to assemble, and more experience.  The crimp-on's require exactly the right tools, the best of which are anything but cheap, but "works pretty well" tools can be obtained at a fair price, and it does not take too much training to put them on.  Don't forget the heat shrink though......   

 

Good point about blowing the finals in the radios due to high VSWR caused by bad crimp on connectors.  

 

To each their own I guess.  

 

Mark

 



________________________________



From: owner-yak-list-server(at)matronics.com on behalf of Jan Mevis

Sent: Sun 7/8/2012 2:52 PM

To: yak-list(at)matronics.com

Subject: Re: Antenna Yak52






I've crimped hundreds of BNC connectors on coax, back in the eighties when

twisted pair was not used yet for Ethernet. And it took a while before I

was reasonably proficient.



In those days we had to use the crimp tool just because of "production

speed".



I also have seen two radio's with their end amplification transistor blown

up because of a BNC connector, crimped on the coax, and became loose.



I prefer soldering but must also admit that I often take the crimp tool,

just because it's so easy to use. Soldering a BNC connector is not that

simple either, for the layman, isn't it?



Jan

On 08/07/12 19:05, "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E"

<mark.bitterlich(at)navy.mil> wrote:



 	  Quote: 	
		  

MALS-14 64E" <mark.bitterlich(at)navy.mil>



Hello Brian,



I have been expecting your reply to be honest.



First, ... Hey Walt, you're correct (and so is Brian) RG-400 is just fine



Brian, you are welcome to disagree with me.  There are many grades and

types of crimp on connectors.   And obviously they would work, or there

wouldn't be so many out there.  My personal bias is based on the 42 years

of experience I have had with them on aircraft.  Some gas tight crimps

that are out there, specifically the types I normally see on 20 Ghz Gore

Line for example are indeed superior to anything else made.  These are

typically factory assembled and are not repairable in the field.  If they

are, you can only replace the end fitting, and not swage in a totally new

connector to the transmission line itself.  In addition, keep in mind

that I am talking to aircraft owners/pilots, who might want to repair

their own aircraft.



Typical crimp on connectors, are not gas tight.  In fact, there is

special coax designations, or "MilSpec" if you will, that are

specifically designated for gas tight crimps.  RG-142, 400, 214, 393,

etc., are not gas tight transmission lines.  But yes,.. you could use gas

tight crimps on them if you wanted.  What I am referring to is what I'll

call  "The Standard Crimp on Connector".  If these are assembled and

crimped on properly....



WAIT WAIT !!!!!  There is that sneaky "IF" word that just crept in.  The

"IF" means that you have in your hands, the exact correct type of crimp

tool, properly adjusted, and know how to us it ... if all that is true,

you can create a good operational RF connector on the end of the

transmission line.  But it is not gas tight, any more than a manually

assembled connector.  You mention this yourself when you commented on a

properly ratcheting crimp tool.  And in most cases, an aircraft

owner/operator is not going to go out and purchase the best quality

crimping tools and dies out there.  Avionics Shops might... maybe.  Not

always.



Yes, there is indeed a special connector, historically tracing it's roots

back to the RayChem company, that has self sealing heat activated

material inside.  Now we need the proper heat gun, ... or you can just

wild ass guess it with a hot air gun, and in this case a seal is made,

that is probably a tad superior to the rubber self split ring concept of

the manually made connectors.  However, I mildly object to the term "gas

tight" as that is a phrase normally reserved for connectors designed to

be used on specific gas tight transmission lines.  However, given what we

are talking about here, it really doesn't matter.



Finally, we get to the heat shrink tubing that you mentioned putting on

the outside of the coax line.  This is the most important thing you said

... in my opinion. Typical crimped connectors put a physical stress point

on the coax line itself, causing premature failure right behind the

connector.  Putting not only heat shrink, but the proper TYPE of heat

shrink over that possible flex point, will improve the life of the crimp

on connector.  But then, it will do the exact same thing on a manually

assembled, soldered center pin connector.  So heat shrink installed on

ANY connector is by and large "A GOOD THING".



You mention that crimp on connectors with heat shrink backing "IS BEST

STANDARD PRACTICE".   Well, I guess that depends on what standards you

are referring to  Clearly they are best by your standards,



You then said:  "That is why good radio shops use this approach over and

over again with good success. If it didn't work, they would be losing

money on rework so would change their techniques."   That is, in my

opinion, flawed reasoning.  With the General Aviation Avionics Shops that

I have experience with, if something works going out the door, and then

you come back a year later with a damaged connector, they are not going

to fix it for free because it did not last as long as you thought it

should.  They will fix it exactly the same way again, and charge you for

it.  Avionics shops are out to make money, and very few of them sacrifice

their time to make a connector last longer.  I am well aware that using

crimp on connectors is "standard practice" for most shops, but that does

not make it the "best method", it makes it the fastest and cheapest

method, and THAT is what they are looking for.



AND... of all the connectors I have seen Avionics Shops put on, few if

ANY put heat shrink on the back, and NONE have ever used a connector with

internal heat activated sealant.  Those types cost too much.



The reason I prefer the type I promoted Brian, is because I have been

working with these types of connectors for 42 years on military aircraft,

every single day.  It is true that crimp connectors can be made to last

longer.  However, the manually soldered on types that I prefer, with heat

shrink on the back, last longer than anything else.



Antennas ... interesting that you brought that up.  The mechanical bond

between aircraft skin and antenna is obviously critical for best

performance.  A funded study was performed on this issue about 15 years

ago by the Department of Defense,   This is a significant issue,

especially for USN, and USMC aircraft as they operate in highly corrosive

environments.  The result of this study is that now all USN and USMC

aircraft use a very special conductive sealing method for all external

antennas.  Give a Google look-up for: "AV-Dec" and read all about it

there.  AV-Dec is NOT "best standard practice" by any means.  It is BEST

POSSIBLE PRACTICE, and I've yet to see it used in General Aviation,

except on my aircraft of course.



You said: "This is not rocket science".   Correct, far from it.  Actually

it is your and my OPINIONS being expressed on the YAK List.  Not even

close to Rocket Science.  .



Mark



p.s.  The short version:  "I think we'll agree to disagree on this one.

________________________________



From: owner-yak-list-server(at)matronics.com on behalf of Brian Lloyd

Sent: Sun 7/8/2012 4:23 AM

To: yak-list(at)matronics.com

Subject: Re: Antenna Yak52

On Sat, Jul 7, 2012 at 11:35 PM, Walter Lannon <wlannon(at)shaw.ca> wrote:

       

      

       Hi Mark;

      

       Just finishing up the avionics installations in my CJ project.   I used

Mil. Spec. M17/128-RG400  for all units.   2 comms,  TXPDR and GPS.   Had

intended to use RG 142 for the GPS but the local avionics shop (who have

a very good reputation) said the RG400 would be fine.   It's only a 3 ft.

run so I assume either would be OK.   Both are silver plated central

conductor and double silver plated shields.

      

       Do you see any problem with that?

      

Nope. RG400 is functionally equivalent to RG-142. The teflon dielectric

and double-shield, silver-plated braid are the keys. And Mark is right

that these coax cables last a lot longer than cheaper RG-58. If you are

going to spend several thousands of dollars on your radios, trying to

save $50 on your coax feed-line is silly.



The one thing I disagree with Mark on is the use of crimp-on connectors.

I use crimp-on connectors for everything. Turns out that crimping makes a

superior gas-tight connection which makes the connection last longer and

be less subject to failure. Combine that with proper application of

self-sealing (heat-activated adhesive inside) heat shrink tubing and you

have a superior termination even to solder-on terminations. That it is

easier and faster to do is just a plus. (You need a good ratcheting crimp

tool with the proper dies tho'!)



And, no, I am not looking for an argument. The information is available

from the manufacturers of the connectors. They have done the testing and

will provide the results if you are interested.



The key here is that you will have no trouble finding best standard

practices in the industry. It is what good radio shops use. Good quality

coax, e.g. RG400, properly terminated with crimp-on connectors, sealed

with self-sealing heat-shrink, IS best standard practice. That is why

good radio shops use this approach over and over again with good success.

If it didn't work, they would be losing money on rework so would change

their techniques.



One can argue antennas 'till the cows come home but mechanical issues

tend to outweigh the electrical issues. Standard production aircraft

antennas work just fine with standard production aircraft radios. Yes,

you need to make sure that the base of the antenna makes good connection

with the aircraft skin but that just means cleaning any paint or other

coating from the skin around the bolt holes prior to mounting the

antenna. I like to mount my antennas "wet" by applying zinc chromate to

the skin around the bolt holes just before bolting the antenna down. The

wet zinc chromate allows the metals to come together to form an

electrical bond but then the zinc chromate dries to provide a corrosion

barrier.



This is not rocket science.



--

Brian Lloyd, WB6RQN/J79BPL

3191 Western Dr.

Cameron Park, CA 95682

brian(at)lloyd.com

+1.767.617.1365 (Dominica)

+1.916.877.5067 (USA)

brian(at)lloyd.com
Guest

Posted: Sun Jul 08, 2012 12:10 pm Post subject: Antenna Yak52

On Sun, Jul 8, 2012 at 1:05 PM, Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E <mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)> wrote:

  	  Quote: 	
		  You then said:  "That is why good radio shops use this approach over and over again with good success. If it didn't work, they would be losing money on rework so would change their techniques."   That is, in my opinion, flawed reasoning.  With the General Aviation Avionics Shops that I have experience with, if something works going out the door, and then you come back a year later with a damaged connector, they are not going to fix it for free because it did not last as long as you thought it should.  They will fix it exactly the same way again, and charge you for it.  Avionics shops are out to make money, and very few of them sacrifice their time to make a connector last longer.  I am well aware that using crimp on connectors is "standard practice" for most shops, but that does not make it the "best method", it makes it the fastest and cheapest method, and THAT is what they are looking for.

 	




I recommend you contact AMP and get their data on connector reliability.  They make both crimp and solder connectors so they have no axe to grind either way. I think that you might change your mind once you see the figures on failure rates under various stresses. Or not. Both ways work just fine. There is no doubt in my mind but that you can produce an excellent termination using the solder/gasket type connector. I find that MY failure rate is lower with crimp type connectors now that I am using them exclusively. And I use the self-sealing type of heat shrink, of course. It is readily available from marine chandleries if anyone is looking for it and is having trouble finding it. 

 



And you can find it here: http://www.heatshrinktubingdirect.com/adhesive_lined_polyolefin_shrink_tubing.html

 



 	  Quote: 	
		  AND... of all the connectors I have seen Avionics Shops put on, few if ANY put heat shrink on the back, and NONE have ever used a connector with internal heat activated sealant.  Those types cost too much.

 	




Huh. The shops I deal with use heat-shrink. I am trying to remember when a shop didn't but I have to think back to the 70's. But I am sure there are shops that cut corners. Hmm, this might be a way to judge the quality of work coming out of a shop. If the shop does not use heat shrink on the coax connectors then maybe you should be looking for a different shop.

  

 	  Quote: 	
		  

  Antennas ... interesting that you brought that up.  The mechanical bond between aircraft skin and antenna is obviously critical for best performance.  A funded study was performed on this issue about 15 years ago by the Department of Defense,   This is a significant issue, especially for USN, and USMC aircraft as they operate in highly corrosive environments.  The result of this study is that now all USN and USMC aircraft use a very special conductive sealing method for all external antennas.  Give a Google look-up for: "AV-Dec" and read all about it there.  AV-Dec is NOT "best standard practice" by any means.  It is BEST POSSIBLE PRACTICE, and I've yet to see it used in General Aviation, except on my aircraft of course.

 	




Thank you for the information. I will look it up. It sounds good. 

My practice of "wet" assembly using zinc chromate is the technique I was taught while working as an avionics installer back in the 70's. I am sure there are better ways now but the "wet" assembly method works very well and is readily available to people installing antennas on their airplanes using materials that they probably already have in their hangar.

 

-- 

Brian Lloyd, WB6RQN/J79BPL

3191 Western Dr.

Cameron Park, CA 95682

brian(at)lloyd.com (brian(at)lloyd.com)

+1.767.617.1365 (Dominica)

+1.916.877.5067 (USA)

 

  [quote][b]

k7wx

Joined: 24 May 2010
Posts: 117

Posted: Sun Jul 08, 2012 3:49 pm Post subject: Antenna Yak52

Brian,



The purpose of a solder joint is to make the point of electrical contact water tight. Crimping the braid or a center conductor of coax to a BNC connector in any environment with moisture is generally a second best option. For the short term, crimping is fine, but it's never as good as soldering. Anyone who has done antenna work knows this to be true. An alternative would be sealing the connection in something like epoxy, but this is really hard or next to impossible to do for small connectors. Heart shrink tubing does not make a contact water tight, just looks nice. 

I agree with Mark. The reason the people don't do this is because it takes time and practice and is not easy to do correctly. There is even a genuine art to terminating something large, like RG-8 to a PL-259. You would be amazed / disappointed at some of the stuff that comes out of repair stations and is passed off as adequate. May work OK for the short term, which is all that some seem to care about. 

Warren



 

On Jul 8, 2012, at 1:07 PM, Brian Lloyd wrote:

[quote]On Sun, Jul 8, 2012 at 1:05 PM, Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E <mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)> wrote:

  	  Quote: 	
		  You then said:  "That is why good radio shops use this approach over and over again with good success. If it didn't work, they would be losing money on rework so would change their techniques."   That is, in my opinion, flawed reasoning.  With the General Aviation Avionics Shops that I have experience with, if something works going out the door, and then you come back a year later with a damaged connector, they are not going to fix it for free because it did not last as long as you thought it should.  They will fix it exactly the same way again, and charge you for it.  Avionics shops are out to make money, and very few of them sacrifice their time to make a connector last longer.  I am well aware that using crimp on connectors is "standard practice" for most shops, but that does not make it the "best method", it makes it the fastest and cheapest method, and THAT is what they are looking for.

 	




I recommend you contact AMP and get their data on connector reliability.  They make both crimp and solder connectors so they have no axe to grind either way. I think that you might change your mind once you see the figures on failure rates under various stresses. Or not. Both ways work just fine. There is no doubt in my mind but that you can produce an excellent termination using the solder/gasket type connector. I find that MY failure rate is lower with crimp type connectors now that I am using them exclusively. And I use the self-sealing type of heat shrink, of course. It is readily available from marine chandleries if anyone is looking for it and is having trouble finding it. 

 



And you can find it here: http://www.heatshrinktubingdirect.com/adhesive_lined_polyolefin_shrink_tubing.html

 



 	  Quote: 	
		  AND... of all the connectors I have seen Avionics Shops put on, few if ANY put heat shrink on the back, and NONE have ever used a connector with internal heat activated sealant.  Those types cost too much.

 	




Huh. The shops I deal with use heat-shrink. I am trying to remember when a shop didn't but I have to think back to the 70's. But I am sure there are shops that cut corners. Hmm, this might be a way to judge the quality of work coming out of a shop. If the shop does not use heat shrink on the coax connectors then maybe you should be looking for a different shop.

  

 	  Quote: 	
		  

  Antennas ... interesting that you brought that up.  The mechanical bond between aircraft skin and antenna is obviously critical for best performance.  A funded study was performed on this issue about 15 years ago by the Department of Defense,   This is a significant issue, especially for USN, and USMC aircraft as they operate in highly corrosive environments.  The result of this study is that now all USN and USMC aircraft use a very special conductive sealing method for all external antennas.  Give a Google look-up for: "AV-Dec" and read all about it there.  AV-Dec is NOT "best standard practice" by any means.  It is BEST POSSIBLE PRACTICE, and I've yet to see it used in General Aviation, except on my aircraft of course.

 	




Thank you for the information. I will look it up. It sounds good. 

My practice of "wet" assembly using zinc chromate is the technique I was taught while working as an avionics installer back in the 70's. I am sure there are better ways now but the "wet" assembly method works very well and is readily available to people installing antennas on their airplanes using materials that they probably already have in their hangar.

 

-- 

Brian Lloyd, WB6RQN/J79BPL

3191 Western Dr.

Cameron Park, CA 95682

brian(at)lloyd.com (brian(at)lloyd.com)

+1.767.617.1365 (Dominica)

+1.916.877.5067 (USA)

 

   	  Quote: 	
		  



href="http://www.matronics.com/Navigator?Yak-List">http://www.matronics.com/Navigator?Yak-List

href="http://forums.matronics.com/">http://forums.matronics.com

href="http://www.matronics.com/contribution">http://www.matronics.com/contribution



	
[b]

brian(at)lloyd.com
Guest

Posted: Sun Jul 08, 2012 7:14 pm Post subject: Antenna Yak52

On Sun, Jul 8, 2012 at 7:46 PM, Warren Hill <k7wx(at)earthlink.net (k7wx(at)earthlink.net)> wrote:

 	  Quote: 	
		   Brian,



The purpose of a solder joint is to make the point of electrical contact water tight. Crimping the braid or a center conductor of coax to a BNC connector in any environment with moisture is generally a second best option. For the short term, crimping is fine, but it's never as good as soldering. Anyone who has done antenna work knows this to be true. An alternative would be sealing the connection in something like epoxy, but this is really hard or next to impossible to do for small connectors. Heart shrink tubing does not make a contact water tight, just looks nice. 

 

	




Warren,

Thank you for your response. It is not my intention to argue. Suffice it to say that I once thought as you do. The connector manufacturers have convinced me otherwise. I recommend you go research their findings on the efficacy of crimping vs. soldering. As a result, I now use crimp-on connectors in preference to soldering. 

 



Now that is not to say that soldering is not good. It is. It is just that, once you fully understand the full mechanism behind the crimped joint, you might change your mind too.

 73 OM



-- 

Brian Lloyd, WB6RQN/J79BPL

3191 Western Dr.

Cameron Park, CA 95682

brian(at)lloyd.com (brian(at)lloyd.com)

+1.767.617.1365 (Dominica)

+1.916.877.5067 (USA)

 

  [quote][b]

mark.bitterlich(at)navy.m
Guest

Posted: Mon Jul 09, 2012 7:44 am Post subject: Antenna Yak52

 	  Quote: 	
		   I recommend you contact AMP and get their data on connector

reliability.  They make both crimp and solder connectors so they have no
	


axe to grind either way. I think that you might change your mind once

you see the figures on failure rates under various stresses. Or not.

Both ways work just fine. There is no doubt in my mind but that you can

produce an excellent termination using the solder/gasket type connector.

I never said differently Brian.  I concur that crimp on connectors

exist, that with the proper methods and the proper tools can be made to

work well. I personally do not use them for my applications, and have

had better success with the manually assembled types.  To each his own,

I am not trying to change your mind.  



It would seem to me that since heat shrink on the rear of a crimped on

connector is something we both agree on, that manufacturers would

include a piece of that good heat shrink with the connector itself, and

also include the use of it in their assembly instructions.  Which most

crimp on connector types do not.  Wonder why that is?  



 	  Quote: 	
		   I find that MY failure rate is lower with crimp type connectors now

that I am using them exclusively.
	




Glad to hear it.  



 	  Quote: 	
		   The shops I deal with use heat-shrink. 


	


Glad to hear that too.  



 	  Quote: 	
		   I am trying to remember when a shop didn't but I have to think back to

the 70's. But I am sure there are shops that cut corners. Hmm, this
	


might be a way to judge the quality of work coming out of a shop. If the

shop does not use heat shrink on the coax connectors then maybe you

should be looking for a different shop.



I am sure you are correct.  That said, most people tend to shop by

picking the place with the cheapest price.  



 	  Quote: 	
		   My practice of "wet" assembly using zinc chromate is the technique I

was taught while working as an avionics installer back in the 70's. I am
	


sure there are better ways now but the "wet" assembly method works very

well and is readily available to people installing antennas on their

airplanes using materials that they probably already have in their

hangar.



Zinc Chromate is now listed as "Hazardous Material" and has special

handling and disposal requirements IAW EPA regulations.  

Mark Bitterlich

brian(at)lloyd.com
Guest

Posted: Mon Jul 09, 2012 8:01 am Post subject: Antenna Yak52

On Mon, Jul 9, 2012 at 11:41 AM, Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E <mark.bitterlich(at)navy.mil (mark.bitterlich(at)navy.mil)> wrote:

   	  Quote: 	
		  It would seem to me that since heat shrink on the rear of a crimped on

 connector is something we both agree on, that manufacturers would

 include a piece of that good heat shrink with the connector itself, and

 also include the use of it in their assembly instructions.  Which most

 crimp on connector types do not.  Wonder why that is?

I would guess two things: price and application. The heat shrink costs money and the jobber is going to end up using what he needs for the application anyway. I know I would prefer to cut my heat-shrink myself. I use different lengths and even double application when I am trying to accomplish a specific radius of strain-relief.

 	  Quote: 	
		   > I am trying to remember when a shop didn't but I have to think back to

 the 70's. But I am sure there are shops that cut corners. Hmm, this

 might be a way to judge the quality of work coming out of a shop. If the

 shop does not use heat shrink on the coax connectors then maybe you

 should be looking for a different shop.

I am sure you are correct.  That said, most people tend to shop by

 picking the place with the cheapest price.

Yeah, lowest price is not necessarily the best way to find the best work. Good, Fast, Cheap: pick two.

 	  Quote: 	

 > My practice of "wet" assembly using zinc chromate is the technique I

 was taught while working as an avionics installer back in the 70's. I am

 sure there are better ways now but the "wet" assembly method works very

 well and is readily available to people installing antennas on their

 airplanes using materials that they probably already have in their

 hangar.

Zinc Chromate is now listed as "Hazardous Material" and has special

 handling and disposal requirements IAW EPA regulations.

Well, rattle-cans of zinc chromate are still available at my favorite aviation supply house (Sacramento Skyranch) so I intend to keep using it.

-- 

Brian Lloyd, WB6RQN/J79BPL

3191 Western Dr.

Cameron Park, CA 95682

brian(at)lloyd.com (brian(at)lloyd.com)

[url=tel:%2B1.767.617.1365]+1.767.617.1365[/url] (Dominica)

 [url=tel:%2B1.916.877.5067]+1.916.877.5067[/url] (USA)

  [quote][b]

mark.bitterlich(at)navy.m
Guest

Posted: Mon Jul 09, 2012 8:13 am Post subject: Antenna Yak52

 	  Quote: 	
		  >	Zinc Chromate is now listed as "Hazardous Material" and has

special
	


	handling and disposal requirements IAW EPA regulations.

	

 	  Quote: 	
		   Well, rattle-cans of zinc chromate are still available at my favorite

aviation supply house (Sacramento Skyranch) so I intend to keep using
	


it.



So do I. 



Mark

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