[Heathkit] VTVM Model IM-28

[Bill Cromwell]

On 01/04/2014 07:11 AM, Alf Fisher wrote:
> Hi,
> I have just been given a VTVM Model IM-28 minus its Test Probe and leads.
> I've downloaded the assembly manual so have quite a lot of information about it such as setting up etc.
> I would like to know the type number of the optional RF probe or what is inside it, so that if necessary I can make one.
>
> I don't suppose there are any of these probes around but if there are, I'd be interested.
>
> Vy 73,
> Alf
> G3WSD
>
>
Hi Alf,

I have one of those with no probe and no manual. I have several other 
VTVMs and I had a chat with another ham who has the whole thing with 
probe and manual. There is a 1 Megohm resitor in the probe. I'll have to 
look again to see which mode(s) it's in the circuit and when it's 
switched out. Somebody else will probably get back to you with the 
information before I get the chance to look it up. A home made probe is 
easily doable. It's so easy that even *I* did it - twice. While you are 
at it, build two probes and make the second one an RF probe. A VTVM with 
those probes is handy to have on your bench. But...doesn't it show that 
in the manual?

73,

Bill  KU8H