DX-40/VF-1 chirp continued

[Jim Berry]

Hello Steve,

Me Said: > >a higher voltage supply is probably actually easier to create.

> Steve said:

> I'd be a lil leery of this, because a resistor dropping 400 down to 150
> volts at, say, 30 mils, will be dissipating... um... 7.5 watts. That will
> probably put Heath's choice of temperature-compensating caps in the VFO to
> a real test considering there's no ventilation holes in the VF-1!

Probably is the major cause of the drift problem with the VF-1 that many
have complained about.
>
> >The separate power supply:  Got an old junker tube TV set chassis laying

> Actually, if you're gonna do this, it might be easier to use the HV from
> your transmitter and regulate it TWICE. For example, two external OA2s in

Now here is something to think about and really worth giving a try.

> >were between 50 and 5000 ohms the rasp went away.  I grabbed a 1000 ohm
> >resistor and soldered it across the 47K.
>
> So you can leave the 47K in there since it's effectively swamped
> by the 1K.
> Possibly it was RF feedback; pickup from the DX40 even though you were

> >Last night I got everything all put back together in their respective
> >cabinets.  Looking at this pile of dangerous open power supply.
>
> You should have seen the "open-bench" I cobbled together to power my first
> Galaxy V transceiver. A couple of weeks of that convinced my Dad that he
> really outta spring his hard-earned money for a real Galaxy supply before
> "the kid" electrocuted hisself...

For now I have the external supply covered with a cardboard box.
My one concern was our cat.  He probably would not smell very good roasted.

> If you can do the cascaded regulators thing, you could mount them on a
> minibox at the back of the VF1. Place the box to the side at the back so
> you can watch them as you key; almost as good as watching a pair of 866s!

I have heard of more then one guy jerking out solid state rectifiers and
plugging their old 866's back in so they could watch the glow.  I am really
going to think about the outboard VR tube suggestion.

73 Jim K7SLI

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