[Elecraft] K3 loss of rx signal

[danny.higgins at keme.co.uk]

I had a similar frustrating problem with a BNC patch lead. I bought some cheap leads at a rally and I didn’t notice that the plugs were 75 Ohms. The leads worked OK, but the centre pin was thicker than the 50 Ohm version and it splayed out the centre connector of the socket, so when I plugged a 50 Ohm patch cable back in, the centre pin did not make contact any more. It took me a long time to find the cause, and now all the 75 Ohm leads are in the bin.

73,

Danny, G3XVR

From: Guy Olinger K2AV
Sent: 03 April 2017 11:56
To: LA7NO; elecraft at mailman.qth.net
Subject: Re: [Elecraft] K3 loss of rx signal

Could be a relay, however....

The most common source of intermittents is cords and connectors that are
either only partially connected or have had wires stressed past breaking
but held together intermittently by insulation, or were never soldered, or
were poorly crimped in manufacture.

Banging on the K3 jiggles all the connections on the back of the K3.

Then there's RCA connectors not pushed in all the way or with too-short
pins for the socket and BNC connectors not twisted home.

RULE OUT the connections before tearing apart your K3.

Then inside there are the TMP mini coax connectors inside the K3 not seated
properly. Then pin connections to reseat several times. All these before
relays.

Relays will usually close again by repeatedly going TX RX TX RX TX RX....

Don't ask me how much I tore apart before I figured it out or how close I
came to putting the K3 in the shipping box......

73, Guy K2AV