[Heathkit] Heathkit AT-1 Meter

[Mark K3MSB]

Hi Bob

Kinda figured that.   I put in a Shurite 1 mA meter with the appropriate
shunt.   Working OK on plate,  but very little movement on Grid (but it
does move).  I need to check the schematics.

73 Mark K3MSB

On Wed, Jun 29, 2016 at 3:58 PM, K5MYJ <macklinbob at gmail.com> wrote:

> These POS IRON VANE meters are not repairable. What you are seeing is the
> typical failure of these meters.
>
> The spring is the very thin section of metal between the outer end
> supports ( there are no bearings) and the IRON VANE between the magnets.
> There is no current flowing through the part of the meter that moves.
>
> The Heathkit AT-1, DX-20, and DX-35 all use this POS meter. The DX-40 has
> a real meter.
>
> You could try finding a meter from a DX-35 or you could try a CalRad panel
> meter:
> http://www.calrad.com/all-products/60-series
>
> But trying to fix the original meter is a waste of time.
>
> Bob Macklin
> K5MYJ
> Seattle, Wa.
> "Real Radios Glow In The Dark"
> ----- Original Message ----- From: <hwhall at compuserve.com>
> To: <mark.k3msb at gmail.com>
> Cc: <heathkit at mailman.qth.net>
> Sent: Wednesday, June 29, 2016 10:36 AM
>
> Subject: Re: [Heathkit] Heathkit AT-1 Meter
>
>
>
>> Is it just my eyes, or is there no spring at all in that construction? If
>> not, then what did it rely upon to return the needle to zero when no
>> current flows?
>>
>> The mp4 clip doesn't seem to be running right here.
>>
>>
>> Wayne
>> WB4OGM
>>
>>
>>
>> -----Original Message-----
>> From: Mark K3MSB <mark.k3msb at gmail.com>
>> To: Wayne Hall <hwhall at compuserve.com>
>> Cc: Ronald Youvan <ka4inm at gmail.com>; Heathkit List <
>> heathkit at mailman.qth.net>
>> Sent: Wed, Jun 29, 2016 5:38 am
>> Subject: Re: [Heathkit] Heathkit AT-1 Meter
>>
>>
>>
>>
>> Well,  I further disassembled the meter.   Here's some pix and a short
>> clip to wow and amaze you......
>>
>> www.k3msb.com/at1/front.jpg
>> www.k3msb.com/at1/bottom.jpg
>> www.k3msb.com/at1/top.jpg
>> www.k3msb.com/at1/side1.jpg
>> www.k3msb.com/at1/side2.jpg
>>
>> www.k3msb.com/at1/clip1.mp4
>>
>>
>> I see no way to perform any adjustment.  loosening the small screw at the
>> bottom of the meter does nothing.
>>
>>
>> I assume that the two small discs are magnets   I was thinking of holding
>> one and attempting to rotate the other (or perhaps rotate the pointer).
>> Unless there is something that was magnetized during my tests, the only
>> other thing that could have happened to the meter was a force which moved
>> some of the parts, and an opposite force may help.    Of course, it could
>> bust things too.....
>>
>>
>> 73 Mark K3MSB
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> On Tue, Jun 28, 2016 at 11:09 PM, Mark K3MSB <mark.k3msb at gmail.com>
>> wrote:
>>
>> The meter glass,  face, etc was already removed before my last post.
>> The meter has a metal case with glass front.
>> Mark
>>
>> On Jun 28, 2016 11:06 PM,  <hwhall at compuserve.com> wrote:
>>
>> One more thing to try... Apply some moisture to the meter face. "Fogging"
>> it with your breath might be sufficient. Occasionally, some meters can
>> acquire a static charge on the meter face or body that pulls the needle out
>> of place. Plastic body meters seem most likely to do that. Some folks
>> recommend wiping on some thinned soapy water to prevent recurrence.
>>
>>
>> Wayne
>> WB4OGM
>>
>>
>>
>> -----Original Message-----
>> From: Mark K3MSB <mark.k3msb at gmail.com>
>> To: Ronald Youvan <ka4inm at gmail.com>
>> Cc: Heathkit List <heathkit at mailman.qth.net>
>> Sent: Tue, Jun 28, 2016 8:49 pm
>> Subject: Re: [Heathkit] Heathkit AT-1 Meter
>>
>> Ron & Wayne
>>
>> The needle moves a bit when I jiggle the meter.  When I blow on the needle
>> it move freely in the appropriate direction.
>>
>> Using a battery and series resistor the meter fully deflects from "noon"
>> to
>> the right.  Reversing polarity the meter fully deflects from "noon" to the
>> left.  The meter returns to "noon" quickly.
>>
>> There is no adjustment of any kind that I can see.
>>
>> I think the meter is original, it matches the pictures in the manual.
>>
>> Orientation - I'll verify tomorrow but I'm pretty sure the "noon" resting
>> point doesn't change.
>>
>> 73 Mark K3MSB
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