[time-nuts] HPZ3801 Failure
jgray at zianet.com
Thu Feb 4 22:09:20 EST 2016
I just checked and KO4BB already has the power supply info.
On Thu, Feb 4, 2016 at 5:21 PM, paul swed <paulswedb at gmail.com> wrote:
> Daves absolutely correct about working around bad supplies.
> The reason for the preregulator is that it would allow the 3801 to meet
> European ETSI dc voltage standards that goes up to 75VDC on the telco
> battery bus. US can reach 56 VDC.
> Anyhow if thats your only problem then you can solve the problem.
> On Thu, Feb 4, 2016 at 1:39 PM, Artek Manuals <Manuals at artekmanuals.com>
>> Some one reversed engineered the supply about 10 years ago and they posted
>> the schematic on the WEB....The web link I have no longer works so I will
>> email you the schematics of the supply direct.
>> I will check to see if the files are not already up on KO4BB and if not I
>> will post them up there for every one
>> That being said while troubleshooting my own supply this week I have
>> learned the following
>> 1) The supply ( is not a switcher) can be troubleshot on the bench
>> removed ( and unplugged from from the Z3801A.
>> 2) The supply is basically A pre-regulator and two DC-DC converters.By
>> cutting one trace you can separate the two and bypass the preregulator
>> which seems to me to be overkill if you using a good regulated DC supply to
>> feed the thing 36 or more volts into the DC/DC converters is fine
>> 3) The smaller DC-DC converter supplies 5V only ( probably for the
>> receiver ???)
>> 4) The larger Lucent converter supplies =15V / -15V /+5V
>> 5) all the DC-DC outputs can be supplied with separate DC supplies of good
>> On 2/4/2016 12:17 PM, Wes Atchison wrote:
>>> My HPZ3801 has died. It appears the internal DC to DC converters have
>>> The fuses (4) I have found on the boards check good with an ohmmeter. I
>>> have checked voltage on test points where labeled as a supply. No
>>> present. Is there a schematic available somewhere? Has anyone repaired a
>>> Z3801 with similar problems?
>>> Thanks for any help.
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>>> and follow the instructions there.
>> Manuals at ArtekManuals.com
>> This email has been checked for viruses by Avast antivirus software.
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> and follow the instructions there.
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
More information about the time-nuts