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Shortening PowerFLARM Brick Antenna and GPS cables



 
 
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  #21  
Old September 17th 12, 01:22 PM posted to rec.aviation.soaring
[email protected]
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Default Shortening PowerFLARM Brick Antenna and GPS cables

Eric,

Exactly correct. The only benefit to trimming the GPS cable is to reduce (in my case, by almost 12 feet) the excess cable that I didn't want to bundle up and keep secure.

Mark
  #22  
Old September 17th 12, 10:01 PM posted to rec.aviation.soaring
Eric Greenwell[_4_]
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Default Shortening PowerFLARM Brick Antenna and GPS cables

On 9/17/2012 5:12 AM, Jim wrote:


The GPS antenna cable doesn't carry high frequency RF, so tidiness
is

the only value in reducing the length.


Eric, so why do we need a GPS antenna wire if the signal from the
satellite magically gets to the receiver without the RF signal first
going through the antenna wire :=P I'm fairly sure that the GPS
antennas are "active" antennas getting phantom dc power from the
receiver but I thought they only had an amplifier; are you sure they
also have a local oscillator & mixer to convert the RF to an IF (I
guess like an LNB)? Amazing for such a cheap device.


A lot of antenna "pucks" are not just GPS antennas, but GPS receivers.
What comes out of the cable is data, not RF. That's not true of every
GPS "puck", of course, but I think it's true of the PF units. Even if
it's the active antenna type you mention, because the output is
amplified and a lower frequency than the raw GPS signals, the cable loss
would be an issue. So, reduce the cable length for tidiness, not signal
strength.

The dipole antennas are passive, so shortening their cables might
improve their output. Without knowing the cable type, I can't say how
much, but I'd guess the antenna designers chose cable that did not have
significant losses for the length provided.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl
  #23  
Old September 17th 12, 11:34 PM posted to rec.aviation.soaring
Dave Nadler
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Default Shortening PowerFLARM Brick Antenna and GPS cables

On Monday, September 17, 2012 5:02:43 PM UTC-4, Eric Greenwell wrote:
The GPS antenna cable doesn't carry high frequency RF


Wrong.

A lot of antenna "pucks" are not just GPS antennas, but GPS receivers.
What comes out of the cable is data, not RF. That's not true of every
GPS "puck", of course, but I think it's true of the PF units.


Wrong. It's an antenna, NOT a receiver.

Even if it's the active antenna type you mention, because the output is
amplified and a lower frequency than the raw GPS signals


Wrong.

Please don't speculate where people may take it seriously,
even on R.A.S...

Thanks,
Best Regards, Dave
  #24  
Old September 18th 12, 04:53 AM posted to rec.aviation.soaring
Eric Greenwell[_4_]
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Default Shortening PowerFLARM Brick Antenna and GPS cables

On 9/17/2012 3:34 PM, Dave Nadler wrote:
On Monday, September 17, 2012 5:02:43 PM UTC-4, Eric Greenwell wrote:
The GPS antenna cable doesn't carry high frequency RF


Wrong.

A lot of antenna "pucks" are not just GPS antennas, but GPS receivers.
What comes out of the cable is data, not RF. That's not true of every
GPS "puck", of course, but I think it's true of the PF units.


Wrong. It's an antenna, NOT a receiver.

Even if it's the active antenna type you mention, because the output is
amplified and a lower frequency than the raw GPS signals


Wrong.

Please don't speculate where people may take it seriously,
even on R.A.S...

Thanks,
Best Regards, Dave


Well, humph! It wasn't speculation, it was ignorance!

So, are most of the GPS pucks are passive antennas, or are they
amplified but with no frequency conversion? And is it useful to shorten
the cable to increase signal strength?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
  #25  
Old September 18th 12, 07:31 AM posted to rec.aviation.soaring
Darryl Ramm
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Default Shortening PowerFLARM Brick Antenna and GPS cables

Outboard antennas are amplified RF, no local mixer/downconversion.

Darryl
  #26  
Old September 18th 12, 07:31 AM posted to rec.aviation.soaring
Darryl Ramm
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Default Shortening PowerFLARM Brick Antenna and GPS cables

Outboard antennas are amplified RF, no local mixer/downconversion.

Darryl
  #27  
Old September 18th 12, 07:34 AM posted to rec.aviation.soaring
Darryl Ramm
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Default Shortening PowerFLARM Brick Antenna and GPS cables

The only ones "outboard receivers" are things like USB connected pucks, where everything lives in the puck.

Darryl
  #28  
Old January 27th 13, 07:25 PM posted to rec.aviation.soaring
kirk.stant
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Default Shortening PowerFLARM Brick Antenna and GPS cables

On Thursday, September 13, 2012 3:34:16 PM UTC-5, kirk.stant wrote:
As anyone who has one can testify, the cables on the dipole and GPS antennas that come with a PowerFLARM Brick are absurdly long - you could almost mount the GPS puck on your tail!



Has anyone any experience in shortening these cables and reattaching the connectors, or is there anyone out there who can do this for a reasonable fee?



Kirk

66


  #29  
Old January 27th 13, 10:04 PM posted to rec.aviation.soaring
Richard[_9_]
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Default Shortening PowerFLARM Brick Antenna and GPS cables

On Sunday, January 27, 2013 10:25:41 AM UTC-8, kirk.stant wrote:
On Thursday, September 13, 2012 3:34:16 PM UTC-5, kirk.stant wrote: As anyone who has one can testify, the cables on the dipole and GPS antennas that come with a PowerFLARM Brick are absurdly long - you could almost mount the GPS puck on your tail! Has anyone any experience in shortening these cables and reattaching the connectors, or is there anyone out there who can do this for a reasonable fee? Kirk 66


The antennas have a crimp connector so it would be hard to remove and reattach the connectors but it may be possible. The GPS end is usually molded so that would be a problem.

http://www.craggyaero.com/cables_&_antennas.htm

Craggy Aero has GPS antennas with a variety of cable lenghts.

Richard
www.craggyaero.com
  #30  
Old January 28th 13, 10:42 PM posted to rec.aviation.soaring
[email protected]
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Default Shortening PowerFLARM Brick Antenna and GPS cables

See pictures of my PowerFlarm antenna cable shortening project at:
https://sites.google.com/site/threeu...flarm-antennas
There are picuters of the opened GPS mouse.
I am also doing some custom bottom-fed dipoles to suit my needs.
3U
 




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