[Boatanchors] [Milsurplus] Freq Counter

[Michael Bittner]

Hue, thanks for the tip.  There is a 33.3 Ohm power resistor between the power input and the positive terminal of the one electrolytic in the whole thing, a 1000 uF, 50-Volt cap with its negative lead at ground.  So that settled the polarity issue.  Although its VR is an LM 340T5 which is a 5-Volt regulator, I guessed it would be OK to try it on 9 and 12 VDC. 
https://photos.app.goo.gl/fuDnNYb2AJvJtCXX8
It worked on 9 and 12 VDC, but only the two least signifacant digits lit up.  So, its either another swap meet 5 bucks shot or I can somehow fix it.  It has only 4 ICs and they are all in sockets. One a 74LS196, but the other three have what appear to be house numbers so it may not be fixable.

Mike, W6MAB


----- Original Message ----- 
  From: Hubert Miller 
  To: milsurplus at mailman.qth.net 
  Sent: Friday, July 13, 2018 12:15
  Subject: Re: [Milsurplus] Freq Counter


  Mike, I have been in that situation a couple times, and finally what I did was pop off the cabinet, and see how the large lytic caps were

  connected with respect to the power connector.

  -Hue 



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