Repair Boonton sensor 51033 (6E) - Page 1
Forum section: electronics / repair

author: pe2ben
author_rank: Contributor
timestamp: April 27, 2020, 05:30:07 pm
content: Hello everyone,Have someone experience in repairing the Boonton 51033 (6e) sensor (older version with black housing?This sensor failed during zeroing.Or does someone knows which diodes are used in this probes?Thanks Ben

author: edpalmer42
author_rank: Super Contributor
timestamp: April 27, 2020, 05:53:32 pm
content: Here's some info that I saved many years ago.https://web.archive.org/web/20061216013712/http://members.shaw.ca/novotill/MillivoltmeterRfProbe/index.htmYou're on your own for a translation of the French document.Ed

author: pe2ben
author_rank: Contributor
timestamp: April 27, 2020, 10:00:25 pm
content: Thanks Ed,Unfortunately this for the Boonton voltmeter ( 1.2 GHz) and not for the Boonton power meter (18GHz).I can't find the french text.But at the end from your link there are some information on diodes when i don't find the original ones.Someone another suggestion?Regards Ben

author: edpalmer42
author_rank: Super Contributor
timestamp: April 27, 2020, 11:52:56 pm
content: Quote from: pe2ben on April 27, 2020, 10:00:25 pmSorry Ben, I didn't look close enough at the page. I guess there's more than one version. Let's try again with a pdf.The French text is in the document that's attached to my previous message.Ed

author: Kosmic
author_rank: Super Contributor
timestamp: April 29, 2020, 01:34:31 am
content: Some more info here. again in french.http://www.voilec.com/ham/boonton.php#repaSo the diodes appear to be paired and the copper foil on the diode has been manually placed to adjust the frequency response of the diode. Also, old probes can develop a lot of attenuation in low frequency but not in high frequency. This would be due to some oxidation in the probe and can be removed by carefully polishing the oxidized parts. The author of the web page was also looking for the correct replacement part for the diodes. he says they are better than BAT 1503.If you need some paragraphs to be translated let me known.

author: pe2ben
author_rank: Contributor
timestamp: May 04, 2020, 09:59:33 pm
content: Many thanks Ed and Kosmic,Looks great !It's a good start point.Regards Ben

author: 1audio
author_rank: Frequent Contributor
timestamp: September 14, 2021, 01:42:31 am
content: I'm undertaking something similar. However its a power sensor. I found the French note on repair but have determined that this guy is completely fried. The 2 100 Ohm resistors are open and the resistors in series with the diodes are open. The diodes are shorted.I think I can replace these components but the construction has a cap that seems buried under solder on the input.Does anyone have experiece rebuilding one of these? Modern parts are potentially much better but the actual optimization will be challenging at best. Is it worth the effort? (I got the sensor for $30.)

author: 1audio
author_rank: Frequent Contributor
timestamp: September 15, 2021, 11:38:02 pm
content: Here are some closeups of the internals of the sensor. There are 2 diodes and 4 "rod" resistors. All of them are fried. The diodes look a lot like HP 5082-2835's. I found some on e-bay. I have a good supply of 5082-2810 but my understanding is that they are less suited to this application. I found a source for the "rod" resistors- Smiths interconnecthttps://www.smithsinterconnect.com/contact/distributor-stock-check/but the prices and availability is not going to work. I'm planning to substitute some RF 0604 resistors and hope for the best.