[Heathkit] HR-10 Improvement on 10/15 ?

[Drew P.]

Paul wrote:

> Today I substituted a signal generator for the LO and as
> expected the 
> 10M and 15M performance improved dramatically (just a few
> dBs down on 
> the other bands). It requires about 6V P/P at the true
> RF+IF 
> frequency. Now to make the internal LO do that.

Part of the solution may be also increasing drive to the mixer at the oscillator fundamental frequency.  This would cause more harmonic generation within the mixer itself. A combination of this and external harmonic enrichment via an added asymmetrically-clipping buffer stage might be used.

You could try reworking the oscillator to run at the correct injection frequency (not at a subharmonic), but this probably would have more than its share of problems, else Heath would've designed it that way.

Drew