[Boatanchors] Making Stable Inductors for 2 MHz

[Jim Wiley]

This is an interesting problem.   One possibility that could get around 
some of the stability and keying issues (slow oscillator starting times, 
etc. ) would be to let the oscillator (or oscillators) run continuously, 
and send the output through a gating circuit that could be set to 
provide the appropriate 30 to 40 microsecond "on" times together with 
the needed "off" period for the demonstration signal.  It would even be 
possible to combine the gates with zero-crossing detectors to provide 
"perfect" outputs, that is to say free from transients caused by 
starting or stopping at some arbitrary part of the waveform.   This 
technique should work with either crystal controlled or free running 
oscillators.  If necessary, more than one gate "in series" could be used 
to ensure sufficient isolation, that is to say a 120 dB or better  
reduction from full output.    As I said, and interesting problem, the 
solution to which could provide several hours of entertainment with a 
prototyping board and a box-full of parts on the workshop bench. 


And yes, I too remember the LORAN pulsing in and around the 160 meter 
band, and the joy I felt when I finally found a receiver that had a 
noise blanker good enough to make if go away.  The first instance came 
with a HQ-170 with the optional noise blanker, which  knocked the noise 
down from S9+40 db to maybe S3, which made it possible to carry on a 
QSO.  Later on, I got a Drake R-4C.  It's blanker made the LORAN just 
plain go away.  It was nothing short of amazing.  


- Jim, KL7CC



Drew P. wrote:
> John wrote:
>
> (snipped)
>
> "I'm working on a LORAN-A simulator for the DAS-1 on the MASSACHUSETTS and
> have a design question.
>
> (snip)
>
> 'm now looking at building a stable, keyed oscillator in the above
> frequency range. My intention is to use a SS Hartley or Colpitts."
>
> (snip)