Disassembled the surplus Rx cell by first disconnecting the short jumper cable and then unscrewed the brass part. Inside was a tiny diode, color coded "391" as have been previously discussed in a thread some years ago. I recon that if a diode would some time in the future breakan external multiplier featuring modern semiconductorsshould not be that hard to design and connect directlyto the loop in the other end of the jumper cable.  Actually, I was expecting something in a tiny ceramic package with a UNF thread in one end and a gold plated cap in the other. Not anything that looked like a 1N4148... I could see that the bottom coax part of the SRD assembly had been filled with curing silicone after the diode had been put in place. Removing/replacing it would require using a drilland fixture but it should be doable without cracking the glass... Ulf Kylenfall SM6GXV

Hi As part of your “simple replacement” … keep in mind that it needs to act both as a multiplier *and* as a mixer. The two modes need to be reasonably separate from each other or you (likely) get a real mess. Bob > On Oct 25, 2020, at 4:26 PM, Ulf Kylenfall via time-nuts <time-nuts@lists.febo.com> wrote: > > > Disassembled the surplus Rx cell by first disconnecting > the short jumper cable and then unscrewed the brass > part. Inside was a tiny diode, color coded "391" > as have been previously discussed in a thread some years ago. > > I recon that if a diode would some time in the future breakan external multiplier featuring modern semiconductorsshould not be that hard to design and connect directlyto the loop in the other end of the jumper cable. > > Actually, I was expecting something in a tiny ceramic > package with a UNF thread in one end and a gold plated > cap in the other. Not anything that looked like a 1N4148... > I could see that the bottom coax part of the SRD assembly > had been filled with curing silicone after the diode had been put in place. > Removing/replacing it would require using a drilland fixture but it should be doable without > cracking the glass... > > Ulf Kylenfall > SM6GXV > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there.