Can this be converted?

Hi all

A simple question to get everybody thinking.

Can this be modified/upgraded to work on 70cm/PMR?

It's a LEMM mod. VR122 antenna switch from my bits from the past box




Or can anybody suggest an alternative?

Thanks & best 73

Ray 2290

Hi Ray,

If you're using it as it was intended for as an antenna switch it'll probably be fine as is. (One rig, two antennas.) If you're worried about more isolation then simply swap over the '1' & '2' connectors so that they don't cross over each other and label accordingly. (Plus the switch.) The isolation in the switch would be alright at those frequencies.

You could instead bung some short RG136 coax connections instead of the wire links to perform similar and not worry about re-labelling the box or switch directions. 

I had a dig through my stock and unfortunately I don't have any RG316 left or I'd have sent you some....it's cheap enough in 1m lengths but you might have an issue soldering the shield/braid/ground connection side to those screws or connector casings.

I think it'd be fine as is for an antenna switch but a NanoVNA measurement will give relief and I'd expect at least 70dB of isolation even just on the switch.


If you want to switch two different rigs to one antenna then it'll take a lot more work as you'll have to contend with grounding the other rigs antenna connection to prevent accidentally transmitting from one radio to the other.

Take a look at my antenna switch project on the following link to see what I mean :-

https://charlietangodxgroup.forumotion.com/t6862-homebrew-antenna-rig-switches


On my version I had a good 74dB isolation up at UHF and use the setup to happily switch between my Icom-706MKII and the Leixen VV-898S with VHF/UHF. Even when I had the Ailunce HD1 hooked up the isolation was fine right up to UHF frequencies for both.

I hope that helps mate.  

(Not a sign of a drool inducing silver-plated-mercury-wetted RF coaxial switch needed either! )


All the best,
Victor

Hi Victor

Is was because of your hand built antenna switch that I thought to ask the question.

What I'm going to do is upgrade the thin wire to something a bit thicker and put some heat shrink round it. For protection 

Then it will be asking somebody with a NanoVNA thingy to give it the once over and to see if it works or have I messed up 

Will put up a conversation/upgrade video in the future with testing results

Best 73

Ray 2290

No worries there Ray and I wish you well with it.  
(Usually these sort of things are way simpler than some make out for whatever reason.)

Glad that some of my 'waffling' on the forum helps out!

Look forward to seeing your results and that it accomplishes what you're after.


All the very best to you,
Victor