Re: RX #V6 quits working when ant coax braid is connected #v6

Andy_501 <andrew.webb.501.ve4per@...>

Not recently, but yes I did in late summer 2018. I am inclined to believe it was kind of a multiple associated hit of side forks from a main fork that struck all rooftop antennas (SAT TV, Inet Radio Link, OTA rooftop TV antenna and possibly a ham antenna) simultaneously. I don't think it was a full hit of a main lightning bolt because likely that would have set fire to my residence as well.

  It took out ISP's POE internet antenna interface unit, two HDMI input ports one each in two smart TV's, two wired ethernet NIC cards in two separate PC's , and two video adapter display output ports on another two PC's (network file share server and NLE editing workstation).

My main ham PC USB onboard interfaces/hub disabling the PC entirely (had to replace it) the main LR TV satellite TV receiver, a yamaha two channel USB audio mixer, a Yaesu CAT cable and a SignalinkUSB sound device and I suspect RF input to my FT857.  It took almost 6-8 months to find each of the failed components and replace them one at a time and get back to now where it is almost all, except for the possible protector block in the coax switch, to serviceable. Ham PC new one is a refurbished one about $275 Cdn, FT857 repairs $300 + shipping both ways, Yamaha mixer and Sat TV receiver were under warranty, SignalinkUSB was $175 + $75 for replacement PCB for damaged one (so I could repair it myself but didn't find out I could until after a replacement unit was paid for and shipped to me) .

I was sitting in an armchair at 3:00 AM reading when the bolt struck, and I could tell by the sound of it that likely something might be affected, but had no idea how extensive the final end effects were going to be.

Home network ethernet cables close by runs of audio and USB cables and because it was all close to the ham PC onboard USB hub and network cabling the one hit was able to be induced into so many places because of so many interconnections.

It was not apparent immediately that there was widespread damage to so many components but it did demonstrate how it's effects can be transmitted/induced in so many directions at once and being like a major static discharge any module with any CMOS components at all can be damaged and not show up for a long time.

I had worked in electronics and communications facilities for 35 yrs and never seen such widespread damage as this anywhere. Usually it was just replacing carbon protector blocks or heat coils in landline termination points and reboot a system to be back in business; no such luck in this case.

When I had the SAT TV dish and receiver installed the Bell service tech did not install a ground; I had to fight with Bell engineering management to get them to install one and even then they only put in a 40' run of #16 guage insulated hookup wire as a ground when it should have been in my opinion #6 bare copper stranded ground cable. But then who am I right?

Lightning is very weird, expensive and not a ham's friend at all.

On 2020-02-25 4:58 a.m., Raj vu2zap wrote:
Seriously, did you have a thunderstorm ?

At 25-02-20, you wrote:
Yes I was wondering about something like a lightning hit blowing the surge protector built into the switch so went to check and discovered the radio doesn't even turn on now so tomorrow likely I will have to replace a fuse in the external power supply; just hope the rig wasn't damaged. GRRRRRR I was just getting close enough to try a QSO or two.

On 2020-02-25 1:22 a.m., Raj vu2zap wrote:

Remove the jumper cable between the coax switch and the rig and check for a short.
Happened to me..


At 25-02-20, you wrote:
The rig goes through a coax switch which I can select a 40 M Hamstick whip, a 20 M small loop antenna, and/or 100 W 50 Ohm dummy load. Doesn't matter which ant is selected same situation so it would seem voltage difference would be the most likely place to start.

Power supply is plugged into UPS but antenna grounds are all direct to a dedicated ground rod for radio gear alone. So might be a potential difference between radio ground rod and electrical utility ground rods.

Thanks for the tip Raj

On 2020-02-24 10:50 p.m., Raj vu2zap wrote:

I suspect that your antenna cable is shorted or there is a voltage difference between
your ground and your power supply -ve

When partially plugged in the system behaves like a long wire.

See if your antenna is working with another radio.


At 25-02-20, you wrote:
I finished setting up the rig and moved it into the shack to put it on full blown antenna expecting some better signals that the minor few available from the temp mag mount HF vert on metal deep freeze lid conterpoise.

When center conductor is inserted 60-80 % inserted signals are evident and AM broadcast stations within 100 mi are easily received and BFO calibration can be adjusted properly. But as soon as the connector is fully inserted in antenna and ground braid makes solid connection signals disappear on all bands and there seems to be a flicker in the display. On a couple of occasions the display completely blanks and goes white. Power off reset then restores display but not the signals until coax outer conductor is disconnected. Seems like some sort of ground loop almost connecting through the input????

Any pointers??


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