[Elecraft] Switching P/S Horror Stories

[bfollett]

Gang:

Rick, KC0OV asks about switching supply horror stories.

I have tried several switchers all the way back to one of the first ham
products, the Yaesu pancake for a 747.  (15 years ago?) I had tested it at
home, worked fine, took it on vacation, where I used a G5RV, and found
horrible switching noise on all upper bands -- almost ruined the vacation.

Since then, I have added several to the shack, including a very nice,
105-240V input 2.4A out for the K1 and FT817.  My personal experience
confirms one thought "Regardless of source, don't believe a thing about
someone else's noise tests -- QST included".

Sorry, there is no easy answer here -- other than to say, if you are using a
long run of coax to your antenna, and have a good ground -- most everything
will work.   But if you run ladderline, are portable w/o ground, have a
close by antenna like a MP-1, or run an end-fed with a Z match as I often
do -- You had better run some tests before deciding to use a switcher!

Personally, I carry the Int'l Power Sources CUP36-12-1, with 13.5V output,
with me on all trips.  I use it to charge the batts in the K1 or FT817.
Depending upon antenna, and where I am on a specific band, I "may" be able
to Xmit with it, but I don't expect too....  Its a great supply for
"packing", about the size of a long cigarette pack.

In summation, Rick is right -- "no guarantees".

73, Bob
AB7ST