[Elecraft] My "K2 hetrodynes on startup" claim

[Rick Shindley]

Some time back I posted a question asking if others heard squeals from their
K2's immediately after startup.  Mine had been doing that since the
beginning. I assumed it was something in the K2.  I received many e-mail
replies, all indicating that it was probably power supply-related.

My supply was an old prototype linear I saved from the trash pile at an
engineering firm. The thing had a huge transformer. It has all the internal
appearances of a linear.  There's the pass transistor; there's the small
board with the chip, the V adj pot and the obligatory smattering of R's and
C's; there's the bridge rectifier; and there's the... the uh... toroid...
er... ummm...

I'm dumb.

The supply was actually a hybrid switcher design the firm (rightfully)
abandoned. It was only a prototype and lacked adequate hf filtering.  It was
responsible for the squeals heard by my K2. My apologies for EVEN hinting
that there may be a flight-prone bug in the K2.

I bought a used Astron linear supply today. Well, I assume it's a linear
supply because it has a big transformer and...

Rick KC0OV
K2 1360 (no longer a spread spectrum rig)