[Heathkit] Need IM-16 Solid State Voltmeter Info (Walt - WB2VSJ)

Tue Feb 22 14:01:00 EST 2011

> 
Walt,

Thanks for the response.  Would you please look up the Heath part number/description in your manual's parts list for the power transformer and Zener Diode, so I can research the original voltage spec, etc?  Someone graciously sent me a schematic, which will help me going forward.  It appears that a standard 6-volt replacement transformer  full-waved for DC may work, but I'd like to see what Heath provided initially as a half-wave P/S with the Zener VR.

I assume the calibration info would be the same as for one of the venerable VTVM's.

Jack> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Mon, 21 Feb 2011 19:48:17 +0000
> From: jack m <oldvette at hotmail.com>
> Subject: [Heathkit] Need IM-16 Solid State Voltmeter Info
> To: <heathkit at mailman.qth.net>
> Message-ID: <COL111-W32280D5A0252ECAD616921DED90 at phx.gbl>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> 
> Hi Gang,
> 
> I just came into possession of an IM-16 Solid State Voltmeter which has been partially bubba-butchered internally - someone actually replaced the power transformer and battery with 2 wall warts (internal to the cabinet and rattling around!) - one 7.5 volt AC bucked with or against a radio shark universal transformer, and a 1.5 DC wallwart tied to the battery terminals for the ohmeter function, and they even modified the circuit board to do all this! Maybe not a bad idea, but I'd like to return it to original, since it's complete, and the case, meter, panel, 2-way probe and knobs are all pretty nice and original.
> 
> Does anyone on this list have an e-copy of the manual? I'd like to get the parts list, board x-rays and whatever instructions I can find. I assume the original power transformer was about 10-18 volts AC since there is a 9-volt battery plug inside for battery operation, and I did trace to what appears to be a zener diode right on the transformer secondary and after a half-wave rectifier. Thre are also some mysterious traces and lands under the transformer mounting, which may be used (originally) for a 115/230 VAC selection using a dual-winding transformer primary.
> 
> Thanks 
> 
> Jack 
> 
> ------------------------------
> 
> Message: 2
> Date: Mon, 21 Feb 2011 16:02:22 -0500
> From: "Walt - WB2VSJ" <wb2vsj at earthlink.net>
> Subject: Re: [Heathkit] Need IM-16 Solid State Voltmeter Info
> To: <heathkit at mailman.qth.net>
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset="us-ascii"
> 
> Jack,
> 
> Sorry, no soft copy here, but I got my IM-16 Manual from Pete, Manual man
> at www.manualman.com - very good quality.
> 
> Walt
> WB2VSJ
> 
> -----Original Message-----
> From: heathkit-bounces at mailman.qth.net
> [mailto:heathkit-bounces at mailman.qth.net] On Behalf Of jack m
> Sent: Monday, February 21, 2011 2:48 PM
> To: heathkit at mailman.qth.net
> Subject: [Heathkit] Need IM-16 Solid State Voltmeter Info
> 
> 
> Hi Gang,
> 
> I just came into possession of an IM-16 Solid State Voltmeter which has been
> partially bubba-butchered internally - someone actually replaced the power
> transformer and battery with 2 wall warts (internal to the cabinet and
> rattling around!) - one 7.5 volt AC bucked with or against a radio shark
> universal transformer, and a 1.5 DC wallwart tied to the battery terminals
> for the ohmeter function, and they even modified the circuit board to do all
> this! Maybe not a bad idea, but I'd like to return it to original, since
> it's complete, and the case, meter, panel, 2-way probe and knobs are all
> pretty nice and original.
> 
> Does anyone on this list have an e-copy of the manual? I'd like to get the
> parts list, board x-rays and whatever instructions I can find. I assume the
> original power transformer was about 10-18 volts AC since there is a 9-volt
> battery plug inside for battery operation, and I did trace to what appears
> to be a zener diode right on the transformer secondary and after a half-wave
> rectifier. Thre are also some mysterious traces and lands under the
> transformer mounting, which may be used (originally) for a 115/230 VAC
> selection using a dual-winding transformer primary.
> 
> Thanks 
> 
> Jack 
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> End of Heathkit Digest, Vol 85, Issue 16
> ****************************************