On Fri, 23 May 2008, Tio Pedro wrote:

I assume you want some positive reinforcement to make you feel
good about owning this receiver It get's a five star rating on this
site:

http://www.dxing.com/rx/hq140.htm

Regarding the set only being single conversion on the lower frequencies,
that is not a problem. The double conversion provides improved
image rejection on the higher frequencies, but single conversion
probably offers stronger signal handling capabilities (less likelihood
of mixer overload.) Enjoy the radio.

And that sort of scheme was fairly common. Change one stage of the IF
into a mixer/oscillator, and get better image rejection on the higher
band (which is where they needed it). It was simpler than moving
to the scheme of a crystal controlled converter ahead of a receiver
that always tuned a fixed range and certainly cheaper. I'm not
quite sure why they didn't just keep the stage always in circuit,
your point about eliminating the extra mixer seems a bit much for
the time (when there was a lot less talk of such things).

The SP-600 did it, the later Heathkit transistor portable shortwave
receiver did it, I seem to recall even the HRO-60 did it (complete
with a microswitch that did the switching when the right coil tray
was plugged in).

Michael VE2BVW