[time-nuts] HP 00105 oscillator

Stan Searing stans at sycard.com
Sun Feb 12 12:04:07 EST 2006

It sounds like you have it figured out.
The quick heater is 115 VAC.
For 230 VAC connections, 115 VAC is derived from one of the two
windings of the power transformer.
The other power inputs are 24 and 18.7 VDC.
The +24 VDC is the proportional oven supply and oven driver supply.
The +18.7 VDC (also marked +20 on the schematic) runs pretty
much everything else (the oscillator runs from 6V regulated
from the 18.7, while the oven controller, the AGC and the output
amp run from 18.7).
Yes, there is a 15 VDC low current output that is regulated from
the 18.7 and is intended for the fine EFC potentiometer that
drives the +EFC pin.
And yes, there is a meter output from the oven (the oven heater
voltage is 24V minus the voltage on this pin, so the lower the
voltage on this pin, the harder the oven is being driven).
And finally there is a 5 MHz output (separate from the coax output)
for the HP 105 dividers that generate 1 MHz and 100 kHz.

I have a couple dead 105's.  I think that the ribbon cable inside
the oven melted and shorted on one (taking the power supply with it).
I'm not sure what happened to the other, but I'd like to fix is
someday, so if you find other failure modes, I'd appreciate knowing
about them).

I have an extra manual; $25 plus shipping ($15 plus shipping
if you can get Agilent's permission to put it on the web, and you agree
to scan it and make it available on the web).  Or you can borrow it
to copy/scan if you want to pick-up and drop-off in San Jose.

The 105-6012 schematic is in another manual I have.  Looks pretty
similar, the AGC board (and maybe the external connections) are
a little different.


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Mike Feher
Sent: Saturday, February 11, 2006 6:25 AM
To: 'Discussion of precise time and frequency measurement'
Subject: Re: [time-nuts] HP 00105 oscillator

Horst -

Well, have a good night rest. I did bring one of my oscillators upstairs,
into my lab. The oscillator that is not in pieces. Managed to get it to play
right away. Some of it is coming back to my memory and I believe there are
two ovens. One is a proportionately controlled oven run by the 24 volts, and
the other is a quick oven to get things up to temperature. I am convinced
that the two Teflon connectors are for the quick oven which is controlled by
a thermostat. I put 40 volts on mine and it only drew about 200 ma, but, it
automatically shut off after about 1/2 hour. So, it seems like it may be
working. I believe the terminal marked 15 Volts is a regulated output in
case you want to use it with the EFC inputs through an external multi-turn
potentiometer. The output marked "M" I believe is to monitor the oscillator
status. I tried to replicate the old HP 105 oscillator with my oscillator
assembly and had a meter and a 10 turn pot on the front panel along with a
meter selector switch. I'll try and find the old 105 manual, as I know I
have it someplace. Regards - Mike     

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of A.H.Schmidt
Sent: Saturday, February 11, 2006 8:50 AM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] HP 00105 oscillator

Hi Mike,  thanks for your replay.  I actually have the oscillator going 
since a couple of weeks.  I connected 24V for the oven and 20 V for the 
oscillator. There is also a 15V connection,  I have  no idea what for 
and the 2 connections on the other end which I also don,t know what it 
is for. The voltage control inputs are SMC connections, (I suppose for 
low noise) but there are separate + an _ connections.  I left them open 
and adjusted the frequency with the course frequency control only.
I am comparing the frequency to a home build  receiver for TV line 
frequencies, Phase locket to give me 10 and 5MHz output.

According to the TV station CH9 in Melbourne, they  are locket to a 
Cesium standard.   I can compare the frequency to  9 digits and it 
hasn't moved even 1 digit with  Varying temperatures of about 18 Deg C 
to 38 Deg C (In my Garage).

I am really keen to build this unit in to a box and multiply the output 
by 2 to get 10MHz. However I wait, until I have all the
information on the connections.
Thanks again for the speedy replay.  I am going to bed now, It is 1/4 to 
1 O'Clock in the morning.

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