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Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
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24th Aug 2021, 9:21 pm | #1 |
Octode
Join Date: Jul 2009
Location: Cheshire, UK.
Posts: 1,706
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Triplett edge view meter from HP 5261A
I've had this HP 5261A video amplifier plug-in for a while, the edge view meter was jammed when I acquired it, I've no idea how it got like this.
Yesterday I checked the size of the meter case, as there was another similar one in the offered section, it was the same physical size, but not the same FSD (should be 200uA for the 5261A). OK I thought I'll try & see if it could be fixed or not, after all it couldn't get any more unusable. It wasn't too difficult to open the meter, there are two nylon screws under paper seals, the cover was a little tricky to remove, note there are two nylon washers under the cover (I missed these & had to take it apart again). Once removed I could clearly see two turns of the hairspring were stuck under the pointer mechanism (see arrow, I forgot to take a before picture ). It wasn't too difficult to move them to the other side, where they were supposed to be and after that it was free to move again. When re-assembled it was tested and found to be working fine. David |
24th Aug 2021, 9:40 pm | #2 |
Nonode
Join Date: Oct 2008
Location: Warsaw, Poland and Cambridge, UK
Posts: 2,669
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Re: Triplett edge view meter from HP 5261A
Lovely. The 5261A is very handy. Mine will reliably work the counter with signals of about 300uV, which is pretty good. Did yours have the Nuvistor front end? Mine has, and the foam supporting that subassembly had rotted away and needed replacing.
Chris
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25th Aug 2021, 2:00 pm | #3 |
Octode
Join Date: Jul 2009
Location: Cheshire, UK.
Posts: 1,706
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Re: Triplett edge view meter from HP 5261A
Didn't get quite as low with mine, but then again I don't think the attenuator in the Philips RF source is working fully.
This 5261A is one of the later ones with a FET in the front end, same as shown in the pdf from the BAMA archive, the timebase of the 140A scope underneath does use a few though. And I have another 5261A acquired last year that is definitely older and may have the Nuvistor front end instead. Davud |