On Wed, 2 Nov 2011, Edward Knobloch wrote:


Hi,

I've got an HQ-170C. I'm surprised no one mentioned drift.
It's fine for cw/am, but SSB is a trial, unless you let it run 24/7.
The HQ-170C is the same as the HQ-170, except it includes
the optional clock.

That's true, because while it's multiple conversion, the crystal
oscillator is the second conversion (unlike the Collins sort of design,
where it's a tuneable receiver with a crystal controlled converter ahead
of it), so the receiver has the local oscillator is an LC oscillator
running almost up to 30MHz or, the only difference from the average single
conversion receiver of the era is that when it goes to triple conversion
the LO is offset by 3MHz. Considering that stability was always an issue
when the LO went up towards 30MHz with no synthesizer, the receiver can't
be that different from the average receiver (except to the extent
Hammarlund put into stabilizing the oscillator). As someone once pointed
out, the Collins type arrangement wasn't just to get rid of image
rejection, it allowed for a linear scale that was good for each band, and
kept the LC LO at a reasonably low freqnency.


My receiver required a realignment to get back the very sharp
selectivity designed into it. The audio system has a strange
design, where the level you set the gain control also affects
the audio bandwidth. If the audio is cranked up high,
for weak signal reception, audio bandwidth will be reduced.
It never bothered me, but it is something to be aware of.

Is that the "variable response audio system" mentioned in the "73"
listing? I read the listing as meaning "tone control".


The HQ-170A/VHF (last of the '170 line) added a built-in 2 meter converter
designed by Frank C. Jones.

I was going through more magazines last night, and noticed an ad for that
one. It didn't mention Frank Jones, which seems odd since it does seem a
selling point, his VHF book, all those converter articles (a new device
would appear, like a nuvistor, the transistor, the FET) and he'd issue a
set of articles, new converters for each of the 50 to 420MHz bands using
the new device. When Tapetone, or was it Redline, came out with a new
converter, they featured Sam Harris as a "proud owner".

Michael VE2BVW