Re: uBitx v5 issue

Bill Cromwell


The diodes are not very likey to need replacing. Or do you live in Florida - the lightning capital of the world? An impulse from a nearby lightning strike might take the diodes (and might not). Of course, a direct hit by lightning and they won't help. But you will have bigger problems than the diodes or Q90.


Bill KU8

bark less - wag more

On 11/24/20 6:22 PM, Bob Lunsford via wrote:
Would be nice to install a couple of solder terminals so the two diodes could be easily replaced. I bought 100 switching diodes from Radio Shack when they were business and have only used less than five of the batch. Switching the radio to ground by way of a switch that causes the radio input to go to ground when not being used is another form of cheap insurance.
Replacing the diodes would be much better than replacing Q90 in my book. Less trouble and faster.
Bob — KK5R
On Tuesday, November 24, 2020, 12:44:31 PM EST, Bill Cromwell <> wrote:
Hi Ted,
I am preparing to replace Q90 in my V3 and I will be installing the
diodes. I have used them in other solid state rigs in the past and a
couple of time I have had to replace them (two different radios). The
usual failure mode is for them to fail-short. It becomes obvious then
that they have failed because incoming signals pretty much vanish. In
both cases the rest of the radio was preserved. The sacrificial diodes
did their job.
I have never had any problems with radios that have those diodes
installed. Most of the caveats that have been posted here are
*speculation* about what might happen. It hasn't happened. None of the
posts have asserted that any problem has actually happened. I have two
experiences where the front ends were saved and no experiences where the
diodes caused any problems. And that is experience, not speculation.
Bill  KU8H
bark less - wag more
On 11/24/20 11:40 AM, Ted via wrote:
> Would the common 1n914 serve the same purpose?   Being as common as it
> is, etc.
> Ted
> k3rta

Join to automatically receive all group messages.