Transponder antenna installations

On Feb 7, 7:46*am, Willy VINKEN wrote:
On Mon, 7 Feb 2011 06:18:57 -0800 (PST), JJ Sinclair





wrote:
On Feb 6, 9:57*am, jcarlyle wrote:
JJ, please don't use RG-58 for a transponder cable - it has very high
attenuation per foot. Times Microwave LM240 is a much better choice,
with only 1/3 of the attenuation of RG-58 at 1 GHz. I usually use
Times Microwave LM300, with only 1/4 the attenuation of RG-58, but it
has double the diameter. Both of these cables have a greater than 20
year life outdoors.

-john

On Feb 6, 9:07 am, JJ Sinclair wrote:

I second the L-2, di-pole antenna suggestion, all inside with nothing
sticking out to get ripped off. Carve a1"X 1"X4" balsawood block so
that it matches the inside curve of your non-carbon fuselage, then
glue the antenna vertical to the flat side and the curved side to the
inside aft fuselage. *Keep it about 6" away from metal objects like
your elevator push-rod, etc. Secure the RG-58 lead so that it can't
get tangled with controls and you're good to go.
Hope this helps,
JJ- Hide quoted text -

- Show quoted text -

The Becker 4401-175 manual does say that RG-223/U is preferred over
RGU-58, but it doesn't mention LM-240? As a mechanic I am bound to
follow the appropriate tech data. Does LM-240 use the same BNC
fittings I have in stock? Can I use my crimper? What would my log book
entry say? Installed Becker 4401-175 transponder in accordance with
opinions found on ras?
:) JJ

*'Aircell 5' *is a good substitute for plain vanilla RG 58/U coax
cable.
It fits standard BNC connectors.
Attenuation at 1000 MHz is about 32 dB/100m (compared to 54 for RG58)

Willy VINKEN *-ON5WV-- Hide quoted text -

- Show quoted text -

....and Aircell 5 IS listed in the manual for the Trig transponders.
RG-58 is not.

On Feb 7, 3:27*pm, Grider Pirate wrote:
On Feb 7, 7:46*am, Willy VINKEN wrote:



On Mon, 7 Feb 2011 06:18:57 -0800 (PST), JJ Sinclair

wrote:
On Feb 6, 9:57*am, jcarlyle wrote:
JJ, please don't use RG-58 for a transponder cable - it has very high
attenuation per foot. Times Microwave LM240 is a much better choice,
with only 1/3 of the attenuation of RG-58 at 1 GHz. I usually use
Times Microwave LM300, with only 1/4 the attenuation of RG-58, but it
has double the diameter. Both of these cables have a greater than 20
year life outdoors.

-john

On Feb 6, 9:07 am, JJ Sinclair wrote:

I second the L-2, di-pole antenna suggestion, all inside with nothing
sticking out to get ripped off. Carve a1"X 1"X4" balsawood block so
that it matches the inside curve of your non-carbon fuselage, then
glue the antenna vertical to the flat side and the curved side to the
inside aft fuselage. *Keep it about 6" away from metal objects like
your elevator push-rod, etc. Secure the RG-58 lead so that it can't
get tangled with controls and you're good to go.
Hope this helps,
JJ- Hide quoted text -

- Show quoted text -

The Becker 4401-175 manual does say that RG-223/U is preferred over
RGU-58, but it doesn't mention LM-240? As a mechanic I am bound to
follow the appropriate tech data. Does LM-240 use the same BNC
fittings I have in stock? Can I use my crimper? What would my log book
entry say? Installed Becker 4401-175 transponder in accordance with
opinions found on ras?
:) JJ

*'Aircell 5' *is a good substitute for plain vanilla RG 58/U coax
cable.
It fits standard BNC connectors.
Attenuation at 1000 MHz is about 32 dB/100m (compared to 54 for RG58)

Willy VINKEN *-ON5WV-- Hide quoted text -

- Show quoted text -

...and Aircell 5 IS listed in the manual for the Trig transponders.
RG-58 is not.

We use RG 400 for our transponder antenna cables. Trig says it is
good for up to 8'4".....(So does Garmin.)

Since you can mount the trig transmitter box wherever you need,
staying less than 8' is easy.

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