[Boatanchors] [Heathkit] DX-35 meter

[Bob Macklin]

I screwed up and looked at the DX-40 meter.

The DX-35 does show a 3ma/500 ohm meter. Part number is 407-33.

If it were my unit I would change the meter circuit to the DX-40 version.
It's a better meter.

Bob
K5MYJ
----- Original Message ----- 
From: "Garey Barrell" <k4oah at mindspring.com>
To: "Heathkit Reflector" <heathkit at mailman.qth.net>;
<boatanchors at mailman.qth.net>
Sent: Wednesday, March 04, 2009 3:32 PM
Subject: Re: [Heathkit] DX-35 meter


The DX-35 meter was a Shurite brand "moving vane" type of meter.  These
were the bouncing betty style that took so long to settle after moving
it made it almost impossible to accurately dip a final.  I suspect this
had more than a little to do with the supposed failure-prone power
transformer!  Typically these meters had relatively low internal
resistances.

The DX-40 had a D'Arsonval "moving coil" meter that was much more
civilized!  :-)

Techniques for measuring the internal resistance of meters is covered in
just about any ARRL Handbook.  For a three mA movement, you could just
measure it with a good quality DMM as these put VERY little current
through whatever resistance is being measured, typically in the uA range.

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 4-B, C-Line & TR-4/C Service Supplement CDs
<www.k4oah.com>



Tom Chesek wrote:
> ...but the meter for the DX-40 is a part number 407-46. The original
> question referenced part number 407-33 which is what the assembly manual
> calls for.
>
> Tom K3TVC
>
> .
> ----- Original Message ----- 
> From: "Bob Macklin" <macklinbob at msn.com>
> To: "Tom Chesek" <tchesek at epix.net>; "WØQFC" <erastber at tampabay.rr.com>;
> "heathkit" <heathkit at mailman.qth.net>; <boatanchors at mailman.qth.net>
> Sent: Wednesday, March 04, 2009 5:59 PM
> Subject: Re: [Heathkit] DX-35 meter
>
>
>
>> The schematic shows a 1ma/100ohm meter on the DX-40.
>>
>> Bob Macklin
>> K5MYJ
>> Kent (Seattle), Wa,
>> "Real Radios Glow in the Dark"
>>
>> ----- Original Message ----- 
>> From: "Tom Chesek" <tchesek at epix.net>
>> To: "WXQFC" <erastber at tampabay.rr.com>; "heathkit"
>> <heathkit at mailman.qth.net>; <FLBOATANCHORS at yahoogroups.com>;
>> <boatanchors at mailman.qth.net>
>> Sent: Wednesday, March 04, 2009 2:33 PM
>> Subject: Re: [Heathkit] DX-35 meter
>>
>>
>> The 1984 Master Parts file lists it as a 3 milliamp DC meter. The listing
>> does not give a resistance value.
>>
>> Tom K3TVC
>>
>>
>> ----- Original Message ----- 
>> From: "WXQFC" <erastber at tampabay.rr.com>
>> To: "heathkit" <heathkit at mailman.qth.net>;
>> <FLBOATANCHORS at yahoogroups.com>;
>> <boatanchors at mailman.qth.net>
>> Sent: Wednesday, March 04, 2009 4:09 PM
>> Subject: [Heathkit] DX-35 meter
>>
>>
>> Does any one know the internal resistance of the DX-35 meter p/n 407-33?
>>
>> TIA
>> Gene, WXQFC
>>
>


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