[R-390] SS VR replacement for 3TF7

[Barry]

So, using the VR this way, it functions as a half-wave rectifier and
regulates the positive half-wave?

Sorry, but I'm not that versed in SS VRs.

Thanks,

Barry - N4BUQ (not really meaning to kick a dead horse, but apparently I
have...)

----- Original Message -----
From: <Flowertime01 at wmconnect.com>
To: <r-390 at mailman.qth.net>
Sent: Tuesday, January 03, 2006 6:29 PM
Subject: Re: [R-390] SS VR replacement for 3TF7


> DW Holtman,
>
> An idea back when was to just stuff a silicon diode rated at 1amp and
> 100volts into pins 2 and 7 of the 3TF7 socket.
>
> This blocks the 25.2 volts 1/2 of  the time. The net effect is 12.6 volts
of
> DC.
> No 3.6 watts of heat to radiate.
> The transformer gets a 1/2 cycle rest.
>
> As long as you are poking stuff in the socket add a filter cap.
>
>
> We will get yada yada yada all week for my use of the S word.
>
> Yes, a regulator may offer better performance if the power line shifts.
>
> I live with real weather and when my lights blink, I do not set and wonder
> why my receiver is drifting off frequency. As I am not an OP trying to get
a
> copy these days. When my receiver drifts I get the head sets off and look
out my
> window. There is more to life than my receiver and I would like to
continue to
> enjoy life. My QTH is not a bunker these days. Power line shift is my
first
> clue to bad weather.
>
> Tubes are getting costly. So some do not want to run them on DC filaments
> because some 1920 - 1950 text books suggest DC filaments tend to burn open
at one
> end and thus give tubes a short life. We will likely toss the tube for
noise
> before we burn its filaments open operating it on DC.
>
> DC filaments with no filter are more noisy than AC filaments. This could
be.
> But some filter caps would go a long ways. Maybe DC filaments are better
for
> noise if the source is filtered.
>
> Any way the idea has been presented before. It does work.
> Is it better? I do not know. Is 31 flavors of ice cream enough? What
flavor
> is best?
>
> Why have we not heard about this approach before?
> Read some of the other mail from today.
>
> Roger AI4NI