National Company HRO 500 Receiver Demo on bands 3 & 4 after Spectrum Harmonic Generator repair

The spectrum Harmonic Generator was causing a lot of instability in the ability to hold Sync lock.
With the HF capacitor being microphonic and changing frequency when the receiver is
tapped I had thought this was the total reason for synch lock to go out when the receiver had
even the slightest tap on the side or the tuning knob was rotated.
I had not considered whatsoever Spectrum Harmonic Generator stability issues.
Due to a few loose connections and wires / parts CLOSE to ground then vibration of the
receiver whether tuning it or slight taps to the side WOULD CAUSE the Spectrum generator
to quit for even a microsecond and LOCK would be LOST.
With the Spectrum Harmonic Generator now a solid performer it seems LOCK iw more stable when
the VCO / HF oscillator does LOCK.
Ongoing work would be to find and use the correct transistors for the Spectrum Harmonic Genertor instead of chinese silicon NPN's I am using. Might get more output from
the correct geranium transistors.
The HF oscillator also does not run correctly on bands 1, 2, and 5.
The HF oscillator stability needs to be debugged wiht respect to the band switch
as a small movement of the band switch will cut the HF oscillator off.
There are still MANY problems.
The sweep detector and audio muting circuit does not seem to work right or work at all
at this time and I have pulled the muting transistor and the sweep transistor.
=====
Well update.
I reinstalled the sweep transistor.
I have good and fast LOCK on band #3.
I found that putting two NPN transistors (silicon) for the Blocking osc and
the last transistor (amp) made a good improvement in LOCK.
I could bang on the chassis and the receiver would go out of lock for a few ms but then gain lock again with the sweep transistor installed.
The key here is
1) Have STRONG HF signal.
2) Have STRONG and stable harmonics from the Harmonic Generator section
I need to look at band #4 and see if I can get the HF output a little higher across the band.
And band #5 is completely out. Bands 1, 2 completely not working.

[@dfpolitowski2]

Good job.