[time-nuts] HP-115BR Available
jfor at quikus.com
Sat Oct 6 19:14:17 EDT 2012
Although not applicable when you have burnt parts, the 115BRs have to be
started. They do not autostart by themselves.
Behind the front panel, near the top, are a pair of pushbuttons. You have
to apply power, turn the meter to 10 kHz and push the button to start the
first decade divider, then switch to the 1 kHz and repeat with the 1 kHz
button. Then you have to spin the motor gear to start it turning. BTW, It
will turn in either direction.
> Hi all, you may remember a while back that I put a lot of vintage test
> equipment on the EEVBlog.
> Here is the address of that post:
> Among the pieces was the HP-115BR. Several of you indicated an interest.
> The first offer I got was for $250 and I accepted the offer and emailed
> most of you who also had expressed interest. Before packing it up I
> it in, applied a 100KHZ signal to the input, and nothing happened. The
> voltage monitor meter showed nothing in any position. I opened the unit
> and found that the 24 volt power supply transformer was burnt up. I
> notified the original buyer that there was a problem and I would let him
> know if I could get it repaired and we would go from there.
> Doing some trouble shooting it appeared that the 24 Volt DC line was a
> short to ground. Rather than start lifting leads from terminal strips, I
> ordered and downloaded the User/Service Manual for the unit. It did not
> take long to find that there were 4 Power Transistors that were dead
> shorted. They were the Regulator pair and the Power Amplifier pair.
> Replacements were ordered, installed, and the unit is back in top working
> condition again. It has been on the bench running now for about a day and
> half. Everything looks really, all the outputs have clean on frequency
> signals, the tick pulse is there and the meter shows the correct
> for all positions, as indicated in the service manual.
> I am using a Thunderbolt-Trimble GPSDO to drive my frequency counter. The
> counter has a 100KHz output that is driving the 115BR. I tuned in WWB on
> 5MHz and started setting the 115 to match the time as close as I could.
> Cranking the Milliseconds dial around, I was finally able to get a setting
> where the tick output pulse was occurring in coincidence with the WWV time
> tick. In the past 24 or so hours, it has not changed a bit, still right
> together. An absolutely amazing piece of equipment for being built back
> or so years ago.
> Anyway, I still want to sell it to someone who will give it a good home
> put it to use. You can see by the pictures that there is some paint
> on the front panel where there was an ID tab removed. The insides look
> like brand new! Has a built in 24 VDC power supply so all you need do is
> plug it in to a 110 VAC outlet, put a 100KHZ signal into it, flip the
> internal switch back and forth to start the unit running and then spin the
> internal knurled knob to start the clock. And if you spin it the wrong
> it will actually run backwards as well! Full instructions for starting
> setting the clock are in the manual.
> I have about $50 in parts and a lot of fun time troubleshooting invested
> getting it restored to operation. I am asking $250, plus FedEx shipping
> costs, and will include a set of 4 extra transistors, I bought two sets
> in case, and the User/Service Manual on a CD.
> And oh yes, the original buyer used his funds for another purchase and
> me to go ahead and offer it up again.
> Drop me an email if you are interested. My email address is:
> george at mrrace.com
> If I get multiple offers, I will consider them in the order they arrive.
> George Race
> Albion MI
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> and follow the instructions there.
More information about the time-nuts