Voltage on the case

[XXL]

I’m getting shocked if I touch the amplifier heat sink and/or tx case. Only happens when connected to an antenna, not on dummy load. What could this be ?

It’s connected to a GP antenna so doesn’t need a balun.

[RF-Head]

The problem is your amp
A good amp has a Static protection to ground with a coil

Also whaiting for weeks and weeks now and still no payment Next time please have the money before you order a RIG and now it looks like you bought a cheaper rig..... Good luck with it

[Albert H]

I’m getting shocked if I touch the amplifier heat sink and/or tx case. Only happens when connected to an antenna, not on dummy load. What could this be ?

It’s connected to a GP antenna so doesn’t need a balun.

You've probably got some RF coming back down the coax braid - see if the case is "RF live". If you do have RF on the case, you have a mismatch and you're wasting power back down the coax.

The other possibility is that you've got a cheap 'n' nasty switched mode power supply in the rig, and you've got leakage from the mains on to the "ground" output of the power supply. You might be able to overcome this problem by earthing the case properly (you might just blow fuses if there's a bad leakage fault), or by using a high value resistor from the case to mains earth if you just have "static" levels of leakage....

Incidentally, using a Ground Plane aerial might not obviate a matching transformer or un-un (rather than a bal-un). My ⅝ and ⅞-wave aerials with ¼-wave radials need to be matched to the coax as they inherently show 120Ω or 155Ω matches, and my experimental 0.63-wave aerial has a very strange impedance characteristic, but usefully higher gain than most other monopole designs!

Incidentally the reasons for using ⅜, ⅝ and ⅞-wave radiators are mostly to do with shaping the radiation characteristic according to site height. They're all omni-directional, but all have different "throw":

Radiation Patterns.png

Get EZNEC and experiment with antenna designs on your computer!

[sinus trouble]

Oh XXL! You don't seem to be having much luck lately!

Firstly, a dummy load is resistive and fairly predictable in most applications!

An antenna is a reactive load and highly unpredictable in all applications!

When you say "SHOCK" I doubt it is a belter similar to mains voltage!

As RF-Head and Albert mentioned! Internal capacitance can build up between components and insulators! (Especially in inferior gear)

If the potential difference between your body and the rig are ideal? You will feel it!

Have you grounded the rig to mains earth?

[sinus trouble]

Just to add!

48V sounds like nothing!

Ofcourse it is unlikely to be fatal! But RF energy at that voltage will certainly sting if the conditions are right!

So a warning! Beware!

[XXL]

The problem is your amp
A good amp has a Static protection to ground with a coil

Also whaiting for weeks and weeks now and still no payment Next time please have the money before you order a RIG and now it looks like you bought a cheaper rig..... Good luck with it

When iv had the money iv emailed you asking to pay and you don’t respond for over 2 weeks. That’s no good. It doesn’t give me much confidence sending over such a large amount of money to someone I don’t know.

[RF-Head]

Strange why are you asking every few days if i still have it and a few days a go you ask for the size of the box and when i answer you won't reply it's going for weeks and weeks now and that your friend is giving you the money for it etc etc
I rig needs to be built and i'm sometimes a few days away for my work as i tolt you in the many emails.......
I think you want to have my rig as backup when all your shit rigs not working