Hi Steve,

Thanks for the info. The manual was silent on that issue. I was
concerned that there would be arcing at the switch contacts if
you switched live, so I would try one setting, key it, dip, and
adjust the fine loading, unkey, and then try another coarse load
position, wash rinse repeat... until I got the plate current I
was expecting.

The Swan design was very competent, but very much driven by cost.
That said, it is sort of odd that they used the fancy, but expensive,
7360 balanced modulator tube. I wish they would have used 6146's,
but sweep tubes were so plentiful, powerful, and cheap back then that
they probably were as good of a choice as any.

The drifting problems were the result of Swan's using a single conversion
design. They used a band switched HF VFO to feed their first (and only)
mixer. That decision saved them a whole bank full of crystals, and
another conversion stage. It also reduced the number of conversion
products (spurs) that were drifting around in the cabinet. But the cost
was the introduction of that famous Swan drift to the ham bands.

Another cost reducing measure was to exploit the custom of USB on 20,15,
and 10m, and LSB on 80 and 40m. Swan used hi injection for their mixer
on 80 and 40, and low injection for the rest. That allowed them to get
by with a single BFO crystal, and no USB/LSB switch. Hams didn't like
that, so very quickly, Swan introduced a modification to add a third position
to the REC, CW/SSB switch for "opposite sideband", and added a new crystal.

It's an interesting radio. It won't be my favorite, but I was glad to
get a chance to experience it.

-Chuck


Steve Fritts wrote:
How incredibly rude of "lazy"...I own a 350, love the radio...also own
Icom gear...as for the antenna loading, you need to adjust it while
tuining the radio but with as little power out as possible to save the
finals from going soft on you.

Steve W4SEF


On Wed, 23 Nov 2005 19:26:46 -0500, Chuck Harris
wrote:


I have a silly question about the Swan 350 antenna
loading switch. Did they mean for you to switch it
while the rig was keyed for tuning, or were you
supposed to unkey the rig before switching it?

I've always assumed the later, but...

-Chuck