Thanks for the replies so far.

I am testing with a HP lab quality signal generator so it is not band
conditions.
Frequency calibration seems quite reasonable acroos all the bands.

Found a couple of things today:
In the RF amp circuit,
R2 was only 100 ohms instead of 1K.
C7 at the non V+ side of R2 was not connected to ground.
- Fixed these but didn't seem to make much of a difference

Found that grease from the bearings of the main tuning capacitor had
gotten onto the rotor contacts at the front. I noticed this because when I
jiggle the main tuning knob by accident, the signal level jumped.

I think the mixer and following circuitry is working ok.
Removed the RF input lead to the mixer and directly injected the signal
from my signal generator. With a source of 50 ohms the S meter read S5
across the top 3 bands. When I injected the signal through a 1 K resistor
the signal level dropped as a function of frequency.

I will continue to focuss on the circuitry around the RF amp and possibly
cleaning up the switch contacts. I tried swapping tubes but that made no
difference.


Nice radio though.

Bill, VE3JHU





"Ed Engelken" wrote in message
oups.com...
Bill, that kind of performance is not normal for the HQ-180. How is
the dial calibration on the 15-30 MHz band? Is the calibration good,
but the sensitivity bad? If the local oscillator is off frequency,
sensitivity will be poor and the calibration will be off. If it is
just a sensitivity problem, then look at the RF stage. My HQ-180 dial
calibration is very good on all bands. You should expect sensitivity
and calibration accuracy on the "top band" to be as good as on the
others.

Best Regards,

Ed