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Cursitor Doom <curd@notformail.com>: Aug 19 03:17PM Gentlemen,   One of the drawbacks of attempting to fix vintage stuff is the expected voltage readings given in the service manuals of the day. The manuals usually state that the readings given were measured with analogue VMs of a certain ohms-per-volt rating - most commonly IME 20k. Consequently if you measure with a modern DVM with stupendously high Zin you're screwed and will get unrealistically high values. That's never worried me as I keep a vintage AVO for just such circs. All the British service manuals seem to reference 20k OpV AVOs. However, I'm currently TS on a mid 70s Tek scope the manual for which states the readings given are valid for a meter with a Zin of between 100k and 200k (specifically a Triplett 630NS see link).   Anyone come up with a solution to the problem of making voltage readings on high impedance parts of a circuit with a meter of a different Zin to that used by the people who wrote the service manual?   Never heard of an analogue meter with such a high Zin, but here it is:   https://tinyurl.com/ycjz9l4o       -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.

jurb6006@gmail.com: Aug 19 08:53AM -0700 Put the appropriate resistance across the test leads.

<698839253X6D445TD@nospam.org>: Aug 19 04:13PM Cursitor Doom wrote >Anyone come up with a solution to the problem of making voltage readings >on high impedance parts of a circuit with a meter of a different Zin to >that used by the people who wrote the service manual?   If it is available look a the circuit under test, and see if the high impedance does make a real difference.   Else use the scope probe... Do not some of them modern Di Gital makes also display volts? If meter impdance is too high and no other way add a resistor in parallel to your meter?

tabbypurr@gmail.com: Aug 19 09:24AM -0700 On Sunday, 19 August 2018 16:17:51 UTC+1, Cursitor Doom wrote: > that used by the people who wrote the service manual?   > Never heard of an analogue meter with such a high Zin, but here it is:   > https://tinyurl.com/ycjz9l4o   100-200k is 5-10v scale on a 20k/V meter. Or use a digital & add your R. High R meters give a more realistic reading than old analogues on high R circuitry.     NT

John Larkin <jjlarkin@highlandtechnology.com>: Aug 19 09:24AM -0700 On Sun, 19 Aug 2018 15:17:49 -0000 (UTC), Cursitor Doom   >Gentlemen,   >One of the drawbacks of attempting to fix vintage stuff is the expected >voltage readings given in the service manuals of the day.   Why not ignore the voltage notes and just fix it?     --   John Larkin Highland Technology, Inc   lunatic fringe electronics

Cursitor Doom <curd@notformail.com>: Aug 19 04:41PM On Sun, 19 Aug 2018 09:24:57 -0700, John Larkin wrote:   > Why not ignore the voltage notes and just fix it?   You're obviously not a service engineer. ;-)       -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.

Cursitor Doom <curd@notformail.com>: Aug 19 04:43PM On Sun, 19 Aug 2018 16:13:00 +0000, 698839253X6D445TD wrote:   > If meter impdance is too high and no other way add a resistor in > parallel to your meter?   Oh, I see. I didn't quite understand what Clive was getting at. Would that do the trick, d'ya rechnung?       -- This message may be freely reproduced without limit or charge only via the Usenet protocol. Reproduction in whole or part through other protocols, whether for profit or not, is conditional upon a charge of GBP10.00 per reproduction. Publication in this manner via non-Usenet protocols constitutes acceptance of this condition.

Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Aug 18 07:42PM +0200 >> An omnidirectional antenna. >> <https://antennadeals.com/HD8000.html>   > I just looked up "directional antenna" in a 'shopping" search engine and they seem to cost between around just $4.00 all-the-way-up-to over $6,000 ! I wonder what differences they offer?   Pennysensetivity is a much used tool in production,

Chuck <ch@dejanews.net>: Aug 19 09:38AM -0500 On Sat, 18 Aug 2018 09:46:07 -0700 (PDT), bruce2bowser@gmail.com wrote:     >> An omnidirectional antenna. >> <https://antennadeals.com/HD8000.html>   >I just looked up "directional antenna" in a 'shopping" search engine and they seem to cost between around just $4.00 all-the-way-up-to over $6,000 ! I wonder what differences they offer? The first thing you need to ascertain is if you have a mix of UHF and VHF channels you want to receive. If you don't have any VHF channels, you can buy a UHF only antenna. Then you need to find out the signal strength of the stations in your area. Then buy an antenna-amplifier that will provide adequate gain to reliably receive these stations.

w9gb <gregory.beat@gmail.com>: Aug 18 05:29PM -0700 EATON GFCI's were known to have issues with Radio Frequency (RF). http://www.arrl.org/gfci-and-afci-devices   EATON did have a "swap out" (revised design) for these situations.   gb

"Ian Field" <gangprobing.alien1@virginmedia.com>: Aug 18 07:58PM +0100 <tabbypurr@gmail.com> wrote in message news:f5ca4a4a-c775-4523-8bc1-d255f98d4c2e@googlegroups.com... >> shatters - >> my TV also has some electronics that could fail.   > So plenty to choose from. Motor & magnet is another option.   Choose away - fitting a PTC/NTC where a PTC/PTC should be; usually blows away a few copper tracks.

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