My Simpson 260 won't zero on Rx1 scale even with new batteries...

[mcal...@ksu.edu]

NOTE: Crossposted to r.r.amateur.equipment AND r.r.a.boatanchors

The Rx100 scale on my old Simpson 260 VOM zeroes nicely, but the Rx1
scale won't zero even with new batteries. I haven't looked inside,
but is there an internal pot or something I can tweak so it can be
zeroed on the Rx1 scale?

--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
NRA Life Member & Certified Instructor for Rifle, Pistol, & Home Firearm Safety
Also Certified Instructor for the Kansas Concealed-Carry Handgun (CCH) license

[Chuck Harris]

mcal...@ksu.edu wrote:
> NOTE: Crossposted to r.r.amateur.equipment AND r.r.a.boatanchors
>
> The Rx100 scale on my old Simpson 260 VOM zeroes nicely, but the Rx1
> scale won't zero even with new batteries. I haven't looked inside,
> but is there an internal pot or something I can tweak so it can be
> zeroed on the Rx1 scale?

Check the resistance of your test leads. They may be more resistive
than the meter has zeroing range.

Also check the battery terminals, sometimes if a battery is allowed to
leak it will wreck the low resistance contact that is necessary for the
Rx1 range to work. The battery is sourcing pretty high current in
this range.

-Chuck

[The Shadow]

<mcal...@ksu.edu> wrote in message news:fdb432$m...@unix1.cc.ksu.edu...

> NOTE: Crossposted to r.r.amateur.equipment AND r.r.a.boatanchors
>
> The Rx100 scale on my old Simpson 260 VOM zeroes nicely, but the Rx1
> scale won't zero even with new batteries. I haven't looked inside,
> but is there an internal pot or something I can tweak so it can be
> zeroed on the Rx1 scale?
>
> --

There are schematics and calibration procedures at URL:
http://www.simpson260.com/downloads/downloads.htm

Lamont

[Wes Stewart]

On 25 Sep 2007 08:56:50 -0500, mcal...@ksu.edu wrote:

>NOTE: Crossposted to r.r.amateur.equipment AND r.r.a.boatanchors
>
>The Rx100 scale on my old Simpson 260 VOM zeroes nicely, but the Rx1
>scale won't zero even with new batteries. I haven't looked inside,
>but is there an internal pot or something I can tweak so it can be
>zeroed on the Rx1 scale?

Put a really good short right across the banana sockets and see what
happens.

[Dick]

Thanks. I finally got a manual for the Simpson 262 I bought used
about 45 years ago.

Dick

--
Posted via a free Usenet account from http://www.teranews.com

[Ken Fowler]

On 25-Sep-2007, mcal...@ksu.edu wrote:

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> From: mcal...@ksu.edu
> Newsgroups: rec.radio.amateur.equipment,rec.radio.amateur.boatanchors
> Subject: My Simpson 260 won't zero on Rx1 scale even with new batteries...
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It could be a bad contact on the battery holder or the range switch. R X 1 uses a lot more battery
current than R X 100 so that small internal resistances matter. The usual case is that someone
attempted to measure voltage on the R X 1 setting. There are probably burned resistors in the
ohmeter circuit. There is no internal adjustment for R X 1, AFAIK.

Ken Fowler, KO6NO

[Randy or Sherry Guttery]

mcal...@ksu.edu wrote:
> NOTE: Crossposted to r.r.amateur.equipment AND r.r.a.boatanchors
>
> The Rx100 scale on my old Simpson 260 VOM zeroes nicely, but the Rx1
> scale won't zero even with new batteries. I haven't looked inside,
> but is there an internal pot or something I can tweak so it can be
> zeroed on the Rx1 scale?

No, it's either a (very) bad connection - or quite possibly a cooked R16
- check it - it takes a beating in 260s (should be 11.2 ohms)...

regards,
--
Sherry

A Tender Tale - a page dedicated to those Ships and Crews
so vital to the United States Silent Service:
http://tendertale.com

[Larry]

That 11.2 ohm is what happened to mine.That will keep it from zeroing. Those
precision wire wound resistores for that meter were a little hard to find.
Good luck.
"Randy or Sherry Guttery" <comc...@bellsouth.net> wrote in message
news:sddKi.79675$Lu.6...@bignews8.bellsouth.net...

[Ed G]

> That 11.2 ohm is what happened to mine.That will keep it from zeroing.
> Those precision wire wound resistores for that meter were a little
> hard to find. Good luck.

I would suppose that if one used some fairly high resistance wire, and
had the resistance / foot data for that wire, that they could "wind"
their own 11.2 ohm resistor. I may do that with my 260 some time.

Ed