Empathy List Archives

LC

Lon Cottingham

Thu, May 5, 2022 2:29 PM

Does anyone happen to have an extra original, internal, 50 volt power, supply for a Z3801A? Is so, and you will part with it, please contact me by direct email or phone.

73 de Lon, K5JV
281-795-1335

[3f873278-e972-41bd-8708-c76706ab202a]

Does anyone happen to have an extra original, internal, 50 volt power, supply for a Z3801A? Is so, and you will part with it, please contact me by direct email or phone. 73 de Lon, K5JV 281-795-1335 [3f873278-e972-41bd-8708-c76706ab202a]

PS

paul swed

Thu, May 5, 2022 5:59 PM

Lon just in case they don't you can map modern switchers into the position.
I used Vicors when mine went. They were laying around.
Paul
WB8TSL

On Thu, May 5, 2022 at 12:15 PM Lon Cottingham k5jv@kingwoodcable.com
wrote:

Does anyone happen to have an extra original, internal, 50 volt power,
supply for a Z3801A? Is so, and you will part with it, please contact me
by direct email or phone.

73 de Lon, K5JV
281-795-1335

[3f873278-e972-41bd-8708-c76706ab202a]

time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send
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Lon just in case they don't you can map modern switchers into the position. I used Vicors when mine went. They were laying around. Paul WB8TSL On Thu, May 5, 2022 at 12:15 PM Lon Cottingham <k5jv@kingwoodcable.com> wrote: > Does anyone happen to have an extra original, internal, 50 volt power, > supply for a Z3801A? Is so, and you will part with it, please contact me > by direct email or phone. > > 73 de Lon, K5JV > 281-795-1335 > > > [3f873278-e972-41bd-8708-c76706ab202a] > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-leave@lists.febo.com > To unsubscribe, go to and follow the instructions there.

LC

Lon Cottingham

Thu, May 5, 2022 6:24 PM

Paul, Thanks for the thought. This Z3801A chassis already has an
analog supply built in to drive 50 volt internal supply.
That is why I am looking for the original . Again, thanks for the
thought and 73 de Lon, k5jv.

On Thu, May 5, 2022 at 1:13 PM paul swed paulswedb@gmail.com wrote:

Lon just in case they don't you can map modern switchers into the position.
I used Vicors when mine went. They were laying around.
Paul
WB8TSL

On Thu, May 5, 2022 at 12:15 PM Lon Cottingham k5jv@kingwoodcable.com
wrote:

Does anyone happen to have an extra original, internal, 50 volt power,
supply for a Z3801A? Is so, and you will part with it, please contact me
by direct email or phone.

73 de Lon, K5JV
281-795-1335

[3f873278-e972-41bd-8708-c76706ab202a]

time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send
an email to time-nuts-leave@lists.febo.com
To unsubscribe, go to and follow the instructions there.

time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com
To unsubscribe, go to and follow the instructions there.

Paul, Thanks for the thought. This Z3801A chassis already has an analog supply built in to drive 50 volt internal supply. That is why I am looking for the original . Again, thanks for the thought and 73 de Lon, k5jv. On Thu, May 5, 2022 at 1:13 PM paul swed <paulswedb@gmail.com> wrote: > > Lon just in case they don't you can map modern switchers into the position. > I used Vicors when mine went. They were laying around. > Paul > WB8TSL > > On Thu, May 5, 2022 at 12:15 PM Lon Cottingham <k5jv@kingwoodcable.com> > wrote: > > > Does anyone happen to have an extra original, internal, 50 volt power, > > supply for a Z3801A? Is so, and you will part with it, please contact me > > by direct email or phone. > > > > 73 de Lon, K5JV > > 281-795-1335 > > > > > > [3f873278-e972-41bd-8708-c76706ab202a] > > _______________________________________________ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > > an email to time-nuts-leave@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com > To unsubscribe, go to and follow the instructions there.

EB

ed breya

Fri, May 6, 2022 1:28 AM

Do you happen to know what's wrong with the PS? If you can figure this
out, you can probably fix it. AFAIK the DC-DC converters are still
commodity parts, under a number of brands, so the easiest is if one of
those crapped out. If the problem is in the "other" stuff, you'd need
some reverse engineering and lots of patience. Also remember, there are
some tiny pigtail fuses on the board, so check those first.

Ed

Do you happen to know what's wrong with the PS? If you can figure this out, you can probably fix it. AFAIK the DC-DC converters are still commodity parts, under a number of brands, so the easiest is if one of those crapped out. If the problem is in the "other" stuff, you'd need some reverse engineering and lots of patience. Also remember, there are some tiny pigtail fuses on the board, so check those first. Ed

LC

Lon Cottingham

Fri, May 6, 2022 3:50 PM

Ed,

Thanks for the reply. Great idea, but the old board is missing. I
am building this
unit up from three separate parts units. I have all original parts
and cables, except
for the power supply. The chassis already has an analog power supply
built in with
3 wire line cord to power the original 50 volt switcher. It also has
one of Dave Robinson
G4FRE's great digital clocks built in. It is going to be very nice
semi-original Z3801A
with a clock that can be seen from across the room without having to
have a computer
attached.

73 de Lon, K5JV
281-795-1335

On Thu, May 5, 2022 at 11:56 PM ed breya eb@telight.com wrote:

Do you happen to know what's wrong with the PS? If you can figure this
out, you can probably fix it. AFAIK the DC-DC converters are still
commodity parts, under a number of brands, so the easiest is if one of
those crapped out. If the problem is in the "other" stuff, you'd need
some reverse engineering and lots of patience. Also remember, there are
some tiny pigtail fuses on the board, so check those first.

Ed

time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com
To unsubscribe, go to and follow the instructions there.

Ed, Thanks for the reply. Great idea, but the old board is missing. I am building this unit up from three separate parts units. I have all original parts and cables, except for the power supply. The chassis already has an analog power supply built in with 3 wire line cord to power the original 50 volt switcher. It also has one of Dave Robinson G4FRE's great digital clocks built in. It is going to be very nice semi-original Z3801A with a clock that can be seen from across the room without having to have a computer attached. 73 de Lon, K5JV 281-795-1335 On Thu, May 5, 2022 at 11:56 PM ed breya <eb@telight.com> wrote: > > Do you happen to know what's wrong with the PS? If you can figure this > out, you can probably fix it. AFAIK the DC-DC converters are still > commodity parts, under a number of brands, so the easiest is if one of > those crapped out. If the problem is in the "other" stuff, you'd need > some reverse engineering and lots of patience. Also remember, there are > some tiny pigtail fuses on the board, so check those first. > > Ed > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-leave@lists.febo.com > To unsubscribe, go to and follow the instructions there.

EB

ed breya

Fri, May 6, 2022 6:46 PM

I'm a little confused now about what power supply is at issue. The
normal PS board in the Z3801A mounts on top of the main board, and
provides +/- 15V and +5V to it, to run everything. The PS board also
includes the outer oven control, run from a separate 5V DC-DC converter.
The two DC-DC converters and a bunch of support circuitry are rigged to
run around 24V or 48V nominal, depending on the sub-model.

Is this the board that's missing? If so, now I understand why you're
looking for a whole new one. I was picturing fixing one that's crapped out.

I wouldn't be too picky about getting a 48V one versus 24V one - it's
better than nothing, and it's quite easy to change the external PS to
24V. Go with whichever one you can find.

If you can't find anything at all, and build an alternate system, you'll
need to replicate the outer oven control, besides supplying the main
board power.

Ed

I'm a little confused now about what power supply is at issue. The normal PS board in the Z3801A mounts on top of the main board, and provides +/- 15V and +5V to it, to run everything. The PS board also includes the outer oven control, run from a separate 5V DC-DC converter. The two DC-DC converters and a bunch of support circuitry are rigged to run around 24V or 48V nominal, depending on the sub-model. Is this the board that's missing? If so, now I understand why you're looking for a whole new one. I was picturing fixing one that's crapped out. I wouldn't be too picky about getting a 48V one versus 24V one - it's better than nothing, and it's quite easy to change the external PS to 24V. Go with whichever one you can find. If you can't find anything at all, and build an alternate system, you'll need to replicate the outer oven control, besides supplying the main board power. Ed

time-nuts@lists.febo.com

Internal power supply for Z3801A