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Nightlinks
Junior Member
Username: Nightlinks
Post Number: 29
Registered: 1-2009
| | Posted on Sunday, March 15, 2009 - 9:31 am: | 
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Hello,
Does anyone know if using a elbow connector with a double male connector will have any problems with swr or cause tvi?
The elbow will be connected to the radio then the double male connetor will be connected to the elbow. The other end of the double male connector will be connected to the filter.
CEF#1021
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Tech237
Moderator
Username: Tech237
Post Number: 1129
Registered: 4-2004
| | Posted on Sunday, March 15, 2009 - 9:53 am: |
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Will it work - yes. Would I do it?? Definitely not. Why?? Because every join is a potential source of trouble and signal loss.
In your suggested method, you have 3 joins - radio to elbow, elbow to adaptor, adaptor to filter. Using a SHORT piece of coax you have only 2 joins, so one less place that has the potential to create problems.
As I mentioned each join also contributes to signal loss - now each one is probably only a fraction of a dB (cannot recall the actual figures)with multiple joins that can start to add up. By the time you add the coax to filter, coax to antenna, and if fitted two more joins on a lightning protector you are really starting to ask for issues. Professionally, I have rewired systems, that has so many joins in them that the loss was approaching 3db or more.
The key word in any radio installation is SIMPLICITY - do things the simplest way possible, as this gives you less than can go wrong.
Simon
Tech237
N7AUS
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 4514
Registered: 7-2004
| | Posted on Sunday, March 15, 2009 - 2:27 pm: |
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100% correct simon....however, i DO go:radio>>double male connector>>elbow>>tvi filter currently & have no noticeable effect on SWR/reflected power, or loss of efficiency, as noted on a field strength meter.
i was using ICE tvi filters on individual antenna leads inside my outdoor grounding case, with ICE lightning arrestors in several configurations, both as above AND using short jumpers. not remembering specifics, i found that OCASSIONALLY i would have swr issues with jumpers that i didn't have with barrel connector/elbow -type connections. never really figured out why.
i always use amphenol connectors, no matter what the type. i have found 1 particular USA made silver-teflon pl259 to be of acceptable quality.
i think quality connections, kept to a minimum, are not that much of an issue especially lower in the HF region. 27-28 mhz may be the upper limit.
i am currently using the set up nightlinks describes on both my ar3500 & ic746pro. antenna swr is excellent without a tuner, earth ground i feel is good, the only tvi issue i have at the moment is 20 meters & down on 2 tv's that are NOT fed by rg6 quad coax. when 1 was in a different location & attached to rg6 quad, it had no issues, it is on a shorter piece of coax now, but using some old $4***y rg59 & PHOOEY..... |
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