[time-nuts] HP 10811 update

paul swed paulswedb at gmail.com
Thu Jul 25 13:41:13 UTC 2013


Robert
I can't believe you found the transistor. When I pulled it out last night,
its actually a MPSA18!!! I had not had time to look it up but figured it
was a ebay leftover hunt. :-)
At that price I may order 20 of them. Like the gain.
Thanks.


On Thu, Jul 25, 2013 at 9:28 AM, Robert LaJeunesse <
rlajeunesse at sbcglobal.net> wrote:

> FYI, The MPSA18RLRAG is a stock item at Digi-Key, min beta 500 at 1 &
> 10mA, 45V & 200mA rated, TO-92. $0.33 each.
>
>
> http://www.digikey.com/product-detail/en/MPSA18RLRAG/MPSA18RLRAGOSCT-ND/1139919
>
>
>
>
> >________________________________
> > From: paul swed <paulswedb at gmail.com>
> >To: Discussion of precise time and frequency measurement <
> time-nuts at febo.com>
> >Sent: Wednesday, July 24, 2013 9:29 PM
> >Subject: Re: [time-nuts] HP 10811 update
> >
> >
> >Well learned quite a bit Q4 does have an issue. Further there is a reason
> >it has such high Beta. Its must deliver 30 ma to the oscillator and
> buffer.
> >I was quite surprised by this current level. I was  guessing the
> oscillator
> >was a few mils and the buffer maybe 8.
> >The 2n3904 simply does not cut it. Need to do some digging in the ole
> >transistors.
> >Regards
> >Paul.
> >
> >
> >
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