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Mystery part on schematic

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tub...@myshop.com

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May 22, 2019, 9:16:45 PM5/22/19
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This website discusses it, but never really identifies the part. This is
the meter I am working on and I too wondered what the SA1 and SA2 parts
are. I never saw that symbol.

https://www.antiqueradios.com/forums/viewtopic.php?t=117824

Schematic on the webpage.

Fox's Mercantile

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May 22, 2019, 9:29:18 PM5/22/19
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On 5/22/19 8:16 PM, tub...@myshop.com wrote:
> This website discusses it, but never really identifies the part. This is
> the meter I am working on and I too wondered what the SA1 and SA2 parts
> are. I never saw that symbol.

Bear in mind Radio Shack doesn't make ANYTHING. They are a reseller.
A lot of their gear, is branded Micronta or Realistic.

Secondly, Realistic and Micronta are Japanese suppliers. I wouldn't
expect them to 100% follow US standards for schematics.



--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

John-Del

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May 22, 2019, 9:39:43 PM5/22/19
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Wild guess: spark gaps for protection.

Fox's Mercantile

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May 22, 2019, 9:55:11 PM5/22/19
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Despite posting the forum link where they are identified as Surge
Arresters, Tube Guy posted the "what are they?" question over here.

tub...@myshop.com

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May 23, 2019, 1:13:10 AM5/23/19
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On Wed, 22 May 2019 20:55:03 -0500, Fox's Mercantile <jda...@att.net>
wrote:

>On 5/22/19 8:39 PM, John-Del wrote:
>> On Wednesday, May 22, 2019 at 9:16:45 PM UTC-4, tub...@myshop.com wrote:
>>> This website discusses it, but never really identifies the part. This is
>>> the meter I am working on and I too wondered what the SA1 and SA2 parts
>>> are. I never saw that symbol.
>>>
>>> https://www.antiqueradios.com/forums/viewtopic.php?t=117824
>>>
>>> Schematic on the webpage.
>>
>>
>>
>> Wild guess: spark gaps for protection.
>>
>
>Despite posting the forum link where they are identified as Surge
>Arresters, Tube Guy posted the "what are they?" question over here.

No one on that forum CLEARLY said what they are. Just guesses.....
Guesses are not real answers.....

gghe...@gmail.com

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May 23, 2019, 9:41:57 AM5/23/19
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Some sort of transorb, TVS diode perhaps.
GH

John-Del

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May 23, 2019, 10:08:23 AM5/23/19
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On Thursday, May 23, 2019 at 1:13:10 AM UTC-4, tub...@myshop.com wrote:
Well, here's something 100% accurate: that meter is a piece of shit and of no real value to anyone who requires a good meter and knows how to use one. Total waste of time.

tabb...@gmail.com

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May 23, 2019, 11:25:02 AM5/23/19
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I have a whole pile of cheap meters as well as good ones. They're useful IME.


NT

John-Del

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May 23, 2019, 12:33:59 PM5/23/19
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Like I said..

tabb...@gmail.com

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May 23, 2019, 7:22:54 PM5/23/19
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On Thursday, 23 May 2019 17:33:59 UTC+1, John-Del wrote:
clearly not.

lsmartino

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May 25, 2019, 10:40:08 PM5/25/19
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The first message of the forum link posted by you, clearly stated that the "mistery part" was labeled 39ZR07, and looked like a "disk green cap".

A quick search with Google threw this:

http://www.weisd.com/test/GenericParts_WEISD_view.php?editid1=39ZR07D

39ZR07D NTE Equvilent NTE1V025 MOV 25V RMS DIA=8.5MM 1.7 JOULES ITM=250A CLAMPING VOLTAGE=80V

https://www.datasheets360.com/part/detail/39zr-07d/-178918802698168439/

So it's just a MOV.

tabb...@gmail.com

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May 26, 2019, 1:14:23 PM5/26/19
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> > Like I said..
>
> clearly not.

FWIW I bought them to dot them around in various places where formerly I'd have had to go fetch a nice meter or forego using one at all. They can go where loss or damage are a risk with little concern. They've saved time & enabled quick easy repairs. I don't normally need accuracy or a CAT 3 rating to get something working. They paid back their cost (2.44 each) in a few days IIRC, an ROI that's hard to beat. Any engineer should be able to undersand the utility of that.

Yes I require accuracy at times, and have the datrons to do that. These tiddlers are not for those occasions.


NT

Ralph Mowery

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May 26, 2019, 3:09:29 PM5/26/19
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In article <1e50615d-38e0-4f31...@googlegroups.com>,
tabb...@gmail.com says...
>
> FWIW I bought them to dot them around in various places where formerly I'd have had to go fetch a nice meter or forego using one at all. They can go where loss or damage are a risk with little concern. They've saved time & enabled quick easy repairs. I don't normally need accuracy or a CAT 3 rating to get something working. They
paid back their cost (2.44 each) in a few days IIRC, an ROI that's hard to beat. Any engineer should be able to undersand the utility of that.
>
> Yes I require accuracy at times, and have the datrons to do that. These tiddlers are not for those occasions.
>
>

I have 4 or 5 of the 'Free' Harbor Freight metes. Verified them against
a Fluke meter that was verified against some very high accurate lab
gear. The HF meters are not that far off and work fine especially for a
go/no go test. Does it really matter if the house voltage is 120 or 123
volts ? I have on in my truck and some in places around the house as I
don't want to go the shop on the basement for a better meter.

jf...@my-deja.com

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May 27, 2019, 12:18:13 PM5/27/19
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On Sunday, May 26, 2019 at 12:09:29 PM UTC-7, Ralph Mowery wrote:
> I have 4 or 5 of the 'Free' Harbor Freight metes. Verified them against a
> Fluke meter that was verified against some very high accurate lab gear. The HF
> meters are not that far off and work fine especially for a go/no go test.

My HF meters are all pretty accurate, as long as the battery is fresh. My yellow ones do not have any low-battery indicator, so the only hint is when the readings do not make any sense (which may be a challenge for an inexperienced user).

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