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

Bazz4CQJ · 20th Mar 2023, 3:32 pm

Thanks for the comments. Perhaps I should have said in the OP that I don't own a Boonton, but my interest in them started 5 or 6 years ago at the time that 'Skywave' (SK) inspired a couple of threads about homebrew probes and RF voltmeters, none of which seemed to get remotely close to the sort of performance of the Boonton or the comparable Marconi units.

At the time, I think even less was known about the types of diodes used in the probes than is perhaps known now.

I think there were 5 or 6 published designs (in ham magazines) for RFVM that got discussed in the thread, and those that were investigated and all worked much less well than the published articles claimed.

Re choppers, that's a subject I have no previous experience with, so cannot offer any input.

Were it the case that any hobbyist wanted to build an RF probe /VM today, I'm not sure that any new ideas have appeared in the last few years that would suggest a promising way forward?

Thanks to orbanp 1 for the link to the Boonton re-build article which uses a 'photo MOS relay' to do the chopping; must go off an find out what they consist of! That re-build article is 25 years old, so even that may be ready for a rebuild

B

20th Mar 2023, 3:32 pm	#9
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,934	Re: Boonton RF Probes; Diode Replacement Thanks for the comments. Perhaps I should have said in the OP that I don't own a Boonton, but my interest in them started 5 or 6 years ago at the time that 'Skywave' (SK) inspired a couple of threads about homebrew probes and RF voltmeters, none of which seemed to get remotely close to the sort of performance of the Boonton or the comparable Marconi units. At the time, I think even less was known about the types of diodes used in the probes than is perhaps known now. I think there were 5 or 6 published designs (in ham magazines) for RFVM that got discussed in the thread, and those that were investigated and all worked much less well than the published articles claimed. Re choppers, that's a subject I have no previous experience with, so cannot offer any input. Were it the case that any hobbyist wanted to build an RF probe /VM today, I'm not sure that any new ideas have appeared in the last few years that would suggest a promising way forward? Thanks to orbanp 1 for the link to the Boonton re-build article which uses a 'photo MOS relay' to do the chopping; must go off an find out what they consist of! That re-build article is 25 years old, so even that may be ready for a rebuild B __________________ Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. Last edited by Bazz4CQJ; 20th Mar 2023 at 3:42 pm.