EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: cncjerry on March 02, 2018, 05:23:26 am
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Twice today when unscrewing some coax from my reflection bridge, I got what felt like a nasty little rf burn under my wedding ring. The coax is hooked to an antenna outside and I was tracing from 1 - 30Mhz. If it isn't the TG, I guess maybe static on the antenna? It wasn't a shock like you would get in sox across a floor when touching a radiator, It was more like a circular burn feeling under my ring. Gets my attention, no harm done. Possible? I've had RF burns from my 2KW amp, this felt like a low-level version. Hands were damp both times.
If not the TG, then I have to figure a way to ground that antenna before I blow my SA front end.
Thoughts?
Jerry
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I think the "RF burn" is coming from sheath waves and is proportional to RF power and SWR. I have experienced the effect at power levels <30W for SWR <1:1.5 and would expect the SWR to get much worse if some antenna is swept over a wide range.
On the other hand, a TG usually outputs <+10dBm and does not have any resonant matching network at its output. So I have to doubt it could cause a "burn", no matter how bad the SWR gets.
To be sure, connect your antenna to a high impedance scope input and observe the voltage levels, also for DC.
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Not really a burn, moremmlike I have insulation under my wedding ring. Then It goes away. But it does get my attention.