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

[Paul Baldock]

I have an HR-10 that I am restoring to work with my DX-60. Like most 
(all) HR-10's it is deaf on 10M and 15M. This appears to be due to 
the scheme of using the 2nd harmonic of the oscillator on those. 
bands. The trouble is that there is not very much second harmonic.

So I was thinking of adding a FET buffer to the output of the 
oscillator to generate some harmonics. Unfortunately a simple clamp 
would generate a square wave which only has odd harmonics.  A 1/4 
width pulse train generates a healthy 2nd harmonic, and maybe could 
be implemented.

Any thought on this or other ideas to improve the second harmonic?

Thanks

- Paul