Hi Joe,
Over the years, I've built up a stash of vintage linear warts, to which
I add Power Poles as I find the need for one of them, doing the same for
the cable from the provided PSU. I temporarily patch in one of the
little blue VOMs to verify voltage and current are OK under load. Many
years ago, Henry Ott reminded me that both ends of most digital
interfaces are transmitters, so depending on cable lengths and the
frequency, chokes may be needed on both ends or one in the middle.
For higher voltages, I've used re-purposed Thinkpad PSUs. And I add
chokes at appropriate points if needed. I use the wide band RX of a
Kenwood TH-F6A as a noise probe; it defaults to a loop in the base below
10MHz, but can be overridden by a software switch. Tecsun
shortwave/AM/FM RXs also work well, and are more sensitive.
Watch out for regulated PSUs, which tend to be noisy.
73, Jim K9YC
On 2/17/2025 5:08 PM, Joe Subich, W4TV wrote:
Does anyone have a recommendation for a source of *quiet*
replacements (preferably with 3.5 x 1.35 mm coaxial plug)?
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