[Premium-Rx] RE: HRO-600 Help

[w3jn]

Jim - let us know if we can help.  You need to have a working ref oscillator,  a VCO that can be pulled into the proper range, a working loop filter, and the working logic including phase detector.  A 'scope can pinpoint the problem easily.

73 John
  ----- Original Message ----- 
  From: James C. Garland 
  To: premium-rx at ml.skirrow.org 
  Sent: Monday, March 28, 2005 5:37 PM
  Subject: [Premium-Rx] RE: HRO-600 Help


  Hi Gang,
  Many thanks for your help and suggestions, re tracking down some info on my HRO-600 synthesizer. I'm especially grateful to Jerry Dowell AI6L for scanning the data sheets from the (obsolete) Motorola MECL ICs and sending them to me. Also, thanks to Geoff Fors, who also offered to do the same.  You guys are great!

  Once I fabricate a set of extender boards, I'll try reverse-engineering the synthesizer. I don't know a great deal about synthesizers, but from the parts count I think this is likely a relatively simple 1970-era  "integer-N PLL synthesizer." Basically, a voltage-controlled oscillator is divided by N (an integer selected by the bandswitch) and phase-locked to a reference oscillator (in this case 5 MHz, which I'm guessing is divided down to 1 MHz). The output of the VCO, depending on the N selected, thus can be stepped in 1 MHz increments from 56 MHz to 84 MHz, which is the injection input to the first mixer. I'll know more once I get deeper into the project.

  Again, tnx for the help, and I'll let you all know how the project progesses.

  Regards,

  Jim Garland W8ZR



------------------------------------------------------------------------------


  _______________________________________________

  Premium-Rx Mailing List
  To Post: premium-rx at ml.skirrow.org
  For Info: http://ml.islandnet.com/mailman/listinfo/premium-rx
  Visit the Website: http://kahuna.sdsu.edu/~mechtron/PremRxPage/
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mailman.qth.net/pipermail/premium-rx/attachments/20050328/f67c6050/attachment.htm