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nuckolls.bob(at)aeroelect
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 Posted: Fri Sep 16, 2011 11:17 am Post subject: DIY comm antenna . . . Plan-B |
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A reader asked if there was enough 'meat' in the connector
base to cut an indexing relief for the lockwasher . . . as
opposed to using glue to fixture the washer. The
answer is 'yes'. See Plan-B version below. Thanks Bill!
---------------------------------------------------
On several occasions I've cited a commonly
marketed insulated feed-thru mounting for CB
antennas as suitable for doing your own
comm antenna. I've seen this part in blister
packs in lots of stores for prices ranging from
8 to 12 dollars.
Here's an offering I just spotted on Ebay
http://tinyurl.com/3bq5uhv
[img]cid:.0[/img]
The price is right.
You can put a UHF connector on your feedline and
it will connect directly to this mounting. Alternatively,
a UHF-M/BNC-F adapter will let you use the more
common BNC-CM connector on your coax.
The other end of the adapter is 3/8-24 thread hole.
Silver solder your stainless antenna whisker into a hole
drilled in a stainless 3/8-24 hex bolt. Bugger
the threads on the bolt pretty good (poor boy's lock
screw). Chisel works good, just leave first three threads
untouched so you can get it to start. Coat the threads with
grease and screw it into the adapter.
The internal tooth lock washer goes inside between the
doubler and the connector. The skin+doubler thickness
should be .09" or better and braced against stringers
and/or bulkheads if possible. Make your antenna 22 inches
long (total length of base+whisker).
An improved methodology for keeping the lockwasher centered
on the connector is to cut away .015 to .020" of material
off the face of the hex down to a diameter of .500" as shown
here. You can grip the part in a 3-jaw chuck directly onto the
threads. Don't mash 'em and take very light cuts. A couple of
.005" passes produced this end result with no damage to threads.
[img]cid:.1[/img]
This modification of the base will keep the lockwasher centered
while you bolt everything up. After all is said and done, here's
what your ready-to-install antenna looks like.
[img]cid:.2[/img]
Here's the order of installation on your airplane.
[img]cid:.3[/img]
Bob . . .
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nuckolls.bob(at)aeroelect
Guest
|
| Posted: Sat Sep 17, 2011 8:55 am Post subject: DIY comm antenna . . . Plan-B |
|
|
A reader asked if there was enough 'meat' in the connector
base to cut an indexing relief for the lockwasher . . . as
opposed to using glue to fixture the washer. The
answer is 'yes'. See Plan-B version below. Thanks Bill!
---------------------------------------------------
On several occasions I've cited a commonly
marketed insulated feed-thru mounting for CB
antennas as suitable for doing your own
comm antenna. I've seen this part in blister
packs in lots of stores for prices ranging from
8 to 12 dollars.
Here's an offering I spotted on Ebay
http://tinyurl.com/3bq5uhv
[img]cid:7.1.0.9.0.20110917114941.044e8cc0(at)aeroelectric.com.4[/img]
The price is right.
You can put a UHF connector on your feed line and
it will connect directly to this mounting. Alternatively,
a UHF-M/BNC-F adapter will let you use the user friendly
BNC-CM connector on your coax.
The other end of the adapter is 3/8-24 thread hole.
Silver solder your stainless antenna whisker into a hole
drilled in a stainless 3/8-24 hex bolt. You can purchase
a 3' chunk of 'piano wire' at many hardware stores. 3/16"
diameter is a good size. Bugger the bolt threads pretty good
(poor boy's lock screw). A chisel works good, just leave first
three threads untouched so you can get it to start. Coat the
threads with grease and screw it into the adapter.
The internal tooth lock washer goes inside between the
doubler and the connector. The skin+doubler thickness
should be .09" or better and braced against stringers
and/or bulkheads if possible. Make your antenna 22 inches
long (total length of base+whisker).
An improved methodology for keeping the lockwasher centered
on the connector is to cut away .015 to .020" of material
off the face of the hex down to a diameter of .500" as shown
here. You can grip the part in a 3-jaw chuck directly onto the
threads. Don't mash 'em and take very light cuts. A couple of
.005" passes produced this end result with no damage to threads.
[img]cid:7.1.0.9.0.20110917114941.044e8cc0(at)aeroelectric.com.5[/img]
This modification of the base will keep the lockwasher centered
while you bolt everything up. After all is said and done, here's
what your ready-to-install antenna looks like.
[img]cid:7.1.0.9.0.20110917114941.044e8cc0(at)aeroelectric.com.6[/img]
Here's the order of installation on your airplane.
[img]cid:7.1.0.9.0.20110917114941.044e8cc0(at)aeroelectric.com.7[/img]
Bob . . .
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
| Description: |
|
| Filesize: |
151.94 KB |
| Viewed: |
1622 Time(s) |
|
| Description: |
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| Filesize: |
184.4 KB |
| Viewed: |
1622 Time(s) |
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| Description: |
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| Filesize: |
187.07 KB |
| Viewed: |
1622 Time(s) |
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| Description: |
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