UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

Skywave · 27th Jan 2018, 3:38 pm

Ref. post #85: thank you, John.

That PW article covers much of the guessing that I made in my post about features in the one that I built. To mine, I did introduce one small change: every coil (except the VHF hairspring one) had a link winding that via the coil plug & socket connection, is connected to a BNC plug mounted on the case. To that, I attach a loop probe. That makes usage of this GDO a lot easier. A minor re-calibration of the frequency scale was necessary to accommodate the Z thrown across each coil on account of that modification.
However, for freqs. above 100 MHz approx., I would suggest that a separate VHF GDO would be a good idea. And building one for UHF would be a real challenge!

Al.

27th Jan 2018, 3:38 pm	#89
Skywave Rest in Peace Join Date: Jun 2006 Location: Chard, South Somerset, UK. Posts: 7,457	Re: The Best GDO Ever Made? Ref. post #85: thank you, John. That PW article covers much of the guessing that I made in my post about features in the one that I built. To mine, I did introduce one small change: every coil (except the VHF hairspring one) had a link winding that via the coil plug & socket connection, is connected to a BNC plug mounted on the case. To that, I attach a loop probe. That makes usage of this GDO a lot easier. A minor re-calibration of the frequency scale was necessary to accommodate the Z thrown across each coil on account of that modification. However, for freqs. above 100 MHz approx., I would suggest that a separate VHF GDO would be a good idea. And building one for UHF would be a real challenge! Al.