two way radios

Submitted: Thursday, Jun 14, 2012 at 00:04
ThreadID: 96254 Views:2016 Replies:8 FollowUps:3
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G-day got a question for the two way radio gurus out there .
I recently had some work done to my truck which needed the roo bar to be removed instead of pulling my aerial cables through the cables were cut and coaxial cable joiners were used. So will this effect the radios efficiency one is a HF and the uhf .Any info welcomed thanks.
Happy travels.
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Reply By: Ron N - Thursday, Jun 14, 2012 at 00:10

Thursday, Jun 14, 2012 at 00:10
Duane - I'd expect the co-ax joiners will be just fine as long as they're clean and well-connected, and don't become corroded. Seal the joiners well with some electrical sealant or non-acidic (i.e. - not silicone sealant) urethane type sealer. Corrosion will be rapid in this position unless they're well sealed against moisture and dust.

Cheers - Ron.
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Follow Up By: Stu & "Bob" - Thursday, Jun 14, 2012 at 07:43

Thursday, Jun 14, 2012 at 07:43
Plus wrap them with self-amalgamating tape.

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Follow Up By: Robin Miller - Thursday, Jun 14, 2012 at 08:02

Thursday, Jun 14, 2012 at 08:02
All above good advice.

Note The aerials can bw checked with an SWR meter, the place that did it should have used same to verify.

They are not expensive but you usually need a different model for HF and UHF.

The HF is not very critical anyway and should work so long as there is electrical conductivity thru both sides of the cable and of course no shorts across the cable. (best measured with no aerial connected)
Robin Miller

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Reply By: The Bantam - Thursday, Jun 14, 2012 at 12:07

Thursday, Jun 14, 2012 at 12:07
This all depends on the type of coax Joiners that where used.

snually anybody who cant be bothered doing the job properly by withdrawing the cables and reinstalling cant be bothered using propers coax joiners., and is probaly incapable of properly terminating a plug in the first place.

If they are little white plastic ones.....these come from the TV antenna business and most reputable contractors wont use them in that industry.....they are a cheap nasty DIY product and they are comprehensively unsuitable for radio transmission.

The accessory fitter did the same on my vehicle when the bullbar was repleced as part of an insurance job.

I demanded and got a complete new replacement antenna..which I insisted on fitting myself....insisted and got.

Almost without exception, pannel beaters and the like are incapable and unwilling of making a servicable coax join.

If they are to have any chance of being serviceble they will be all metal and will either be BNC plugs or PL259 plugs, usually used with a joining adaptor.

While proper joiners may be all fine and beaut in theory.....I will not accept them......because there is simply no good reason to tolerate them.

Its not hard to cut the plug off unthread the cables and reterminate after rethreading.

If this is both UHF and HF radios....these turkies have just cost you arround $200 - $400 to have the whole thing back as it was befire they butchered it.

Sorry but this sort of thing pisses me off.

If in doubt take it to a reputable two way radio service for an opinion......if it requires fixing....persue the butchers for the cost.


AnswerID: 488441

Follow Up By: PJR (NSW) - Thursday, Jun 14, 2012 at 12:30

Thursday, Jun 14, 2012 at 12:30
I second Bantams response.

Go to a radio ham or shop and get the cables tested. If the cables fail then you can go back to the repairer and have them either replace the cables or give you the funds to do so.

I would not trust them. Luckily I have test gear to test mine. Any amateur radio op in your area should be happy to test them also. And for nicks.

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Reply By: racinrob - Thursday, Jun 14, 2012 at 12:14

Thursday, Jun 14, 2012 at 12:14
I too have both UHF and HF aerials on my bull bar and I would not be happy (read very very unhappy) if they were cut rather than disconnected.
As some else commented make sure the joins are weather proof otherwise you'll have future problems.

rr VKE237 Sel 6678
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Reply By: Member - Duane A (WA) - Thursday, Jun 14, 2012 at 15:07

Thursday, Jun 14, 2012 at 15:07
Thanks for the replies fellas and the info .It really has got my back up. if this is what they intended doing from the start they should have ran past me first .That is what really makes me mad they made that decision .Thanks again
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Reply By: Member - Anthony W Adelaide - Thursday, Jun 14, 2012 at 17:47

Thursday, Jun 14, 2012 at 17:47
Sounds like very unprofessional behaviour on the part of this ''workshop''

I have just transferred our HF from our 80s to our new touring vehicle (VDJ79R) and when I discussed the job with the guys at the radio shop they mentioned the cables need to be joined with the correct factory issue plugs and it was important to keep joins 100% water/weather proof for good performance.

I would not be happy about it either but I would have raised the issue with them before they touched a thing. It may be hard to get them to rectify things now.

Wooly VKS-737 Mobile 0058

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Reply By: cookie1 - Thursday, Jun 14, 2012 at 19:21

Thursday, Jun 14, 2012 at 19:21
Think of it this way,

every join represents a point of failure, it also provides a path of resistance albeit however minor, this causes reflections in the signal which diminishes the signal strength and quality. In the worst case in could destroy the transmit / output stage of your set.

I would be particularly careful with the HF aerial cabling as this can cause serious burns which take a bit of time to heal and the cost of repairing the unit would be quite heavy.

In my jobs (multi thousands to million dollar installations) I never ever allow joins and will re-pull an entire run should something happen to the cable - at my expense.

I would get a quote from your local friendly qualified radio supplier / installer with a comment as to the current cabling and present it to the company that did this, they should react in a positive way as they are obviously not qualified to do such work and probably are not aware of the potential outcome.


AnswerID: 488461

Reply By: The Bantam - Thursday, Jun 14, 2012 at 19:45

Thursday, Jun 14, 2012 at 19:45
Remember too, there is a special relationship that occurs when an aerial is connected to a tranciever with a nice piece of coax and only the minimum number of terminations.

At its best this relationship is beyond the ability for all but the most sofisticated instruments to measure.

When we consider the price of a HF radio rig, 5 or 6 meters of nice quality, fresh coax in a contunuous length and 2 perfecty terminated plugs is a small thing even if you are paying retail.

Even on UHF, a perfect hygeenic cabling job can make a significant difference, that is hard to put ya finger on.

Radio is one thing where being fussy, pays dividends.

Those of us that are fussy, will often cut off and start agian, if the termination has not progressed perfectly........shortcuts or near enough simply don't pay.


AnswerID: 488469

Reply By: Dion - Thursday, Jun 14, 2012 at 22:03

Thursday, Jun 14, 2012 at 22:03
Hi Duane,
I'll side with those that have advised in getting replacement cables.
I too would not use joiners. Whilst it could be demonstrated that the transceivers are functioning, yeah they tx and rx, are they doing it effectively? Will they be effective in an emergency? As pointed out, you now have additional points of failure, not worth it.

Although I can't see that you have specified the type of UHF antenna, I now know that GME 4075/76 antenna bases that replacement coax runs can be purchased as repair kits. If it is an antenna with a molded in coax cable, then needs complete replacement.

Although I haven't dabbled in HF for quite some time, from my recollection the coax at the antenna was joined with a PL259 plug (multi tap) so only needs coax cable to be re-run so it is continuous with no breaks.

Can you get a radio or instrament fitter to write that they have tested each transceiver with the joins in the coax cable and that any further use of transceiver will result in irreapearable damage. Present that back to repairer/insurer and get the antenna's coax's replaced.

AnswerID: 488498

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