[Milsurplus] TBW on the air

[Mark K3MSB]

Hi Ray

I sent you the picture.  I've received a few questions, some close to
yours.   I'll answer them all in another email when I have some time,
probably in a few days.

No, I'm not using 800 Hz !   Good old 110 VAC.

Mark K3MSB

On Tue, Mar 2, 2021 at 10:54 AM Ray Fantini <RAFANTINI at salisbury.edu> wrote:

> Just curious, did not get the picture being that I no longer subscribe to
> the regular part of the reflector and just use the condensed list and that
> don’t include any attachments.
>
> How did you do the power supply? Did you use the original 800 cycle source
> or did you build something for 60 cycles? The reason I as is that I found
> that using a 60-cycle power supply and the original keying circuit had
> issues with the discharge rate of the increased size of the filter
> capacitors.
>
> The original 800 cycle supply used small filters so between key up and key
> down the discharge rate was so short did not have any issue but when going
> to 60 cycles had to increase the size of the filters and between keying the
> capacitors had enough charge to cause a strange keying chirp from the LO
> and IPA stage. I had to provide external bias to cut off the IPA when the
> key was let up.
>
> Also, how are you addressing the power levels? The original power supply
> had different taps for different power levels and the tune position that
> removed plate voltage from the 803 but still provided screen, something
> that you think would destroy most power tubes but the 803 did not care.
> Think the 803 may be the toughest power tube ever built. Back in the day
> when I ran a TBW asked around and no one I have found has ever seen one
> fail.
>
>
>
>
>
> Ray F/KA3EKH
>
>
> ______________________________________________________________
> Milsurplus mailing list
> Home: http://mailman.qth.net/mailman/listinfo/milsurplus
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Milsurplus at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/milsurplus/attachments/20210302/195d2328/attachment.html>