UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Looking to build RF detector probe for low frequency

G0HZU_JMR · 12th Feb 2019, 10:27 pm

Hi IIR,
For the health and safety comments I was really referring to the classic passive RF probes in the link provided by Bazz4CQJ. This classic screened design is for use with a (grounded?) VTVM but it often gets copied and used with a (floating?) handheld DVM instead.

The design of the floating probes is often based on old designs like the one below where the body of the probe is all metal. Modern designs often use a bare metal tube and the probe croc is soldered or screwed to the tube. In my opinion this type of probe + DVM would be risky to use on vintage tube gear because of the risk of a shock if the croc lead falls off and touches a high voltage point.

It's easy to see examples of probes like this online with a google search for:

RF probe 1N34A

Many of them are built inside an uncoated metal tube and used with a handheld DVM and this doesn't seem like a good idea unless the probe is only used on low voltage, low power equipment.

12th Feb 2019, 10:27 pm	#27
G0HZU_JMR Dekatron Join Date: Sep 2010 Location: Cheltenham, Gloucestershire, UK. Posts: 3,077	Re: Looking to build RF detector probe for low frequency Hi IIR, For the health and safety comments I was really referring to the classic passive RF probes in the link provided by Bazz4CQJ. This classic screened design is for use with a (grounded?) VTVM but it often gets copied and used with a (floating?) handheld DVM instead. The design of the floating probes is often based on old designs like the one below where the body of the probe is all metal. Modern designs often use a bare metal tube and the probe croc is soldered or screwed to the tube. In my opinion this type of probe + DVM would be risky to use on vintage tube gear because of the risk of a shock if the croc lead falls off and touches a high voltage point. It's easy to see examples of probes like this online with a google search for: RF probe 1N34A Many of them are built inside an uncoated metal tube and used with a handheld DVM and this doesn't seem like a good idea unless the probe is only used on low voltage, low power equipment. Attached Thumbnails __________________ Regards, Jeremy G0HZU