Jim, try this link http://octopart.com/info/RCA/2N1701 that first vendor has
them for 5 bucks each, I didn't check shipping.
Get someone you know stateside to buy them and post it to you if you are not
in US. The above vendors don't have many, but I noticed other vendors with
15,000 plus in stock. It's readily available.
Phil
----- Original Message -----
From: "Jim Palfreyman" <jim77...@gmail.com>
To: "Discussion of precise time and frequency measurement"
<time-nuts@febo.com>
Sent: Monday, August 10, 2009 10:36 PM
Subject: Re: [time-nuts] HP 106B quartz frequency standard...the story
Hi Phil,
100% agree. I'm not going to risk a substitute - especially in the crystal
oven.
Unfortunately, check out http://www.americanmicrosemi.com/Shipping/
and see they will charge me US$69.99 which is AUS$100 for posting a
single $8 transistor!
The cheapest I have found so far is down to US$22 postage for a single
transistor.
Regards,
2009/8/11 phil <fort...@bellsouth.net>:
----- Original Message ----- From: "Dave M" <masond...@comcast.net>
To: <time-nuts@febo.com>
Sent: Monday, August 10, 2009 10:10 AM
Subject: Re: [time-nuts] HP 106B quartz frequency standard...the story
Thanks for that! - I do have a number of the 5254L units and one of
them is now being eyed off for organ donation. So thanks to all offers
for the 1854-0003.
The 2N1701 in a T08 is my next quest...
2009/8/10 Dave M <masond...@comcast.net>:
Hi all,
Latest update.
With some help and phone calls from Bill the fault seems to have been
isolated. I have removed Q11 from inside the oven and it is cactus. Q9
is also very suspect so I'm going to replace that for good measure.
Q9 is a 2N1701 in a T08 package. Thanks to various people I should be
able to track one down. Q11 is marked as 1854-0003 and that's an HP
internal number and all I know. Might have to substitute that one.
After all this I have some quality photos and can knock up some good
descriptions of the repairs and the 106B internals if anyone is
interested. Any websites hanging around that want to take what I have?
Regards and thanks to all!
Jim Palfreyman
Jim, the 1854-0003 is a pretty common HP part in older eqpt. ?If you
have
junked 5245L counter handy, it's full of them, especially in the decade
counter PCBs. ?If you don't have one handy, I have an assembly here
with
8
of them on it. ?If you like, I can send it right away (if you're
outside
the
USA, you pay postage).
Dave M
masondg44 at comcast dot net
I went to a bookstore and asked the saleswoman, "Where's the
self-help section?" She said if she told me, it would defeat the
purpose.
Jim,
The NTE sub for the 2N1701 is the NTE152, available from Mouser and many
other suppliers. According to the datasheet, it's in a TO-220 case. If
you
want to try to find a sub in a smaller package, here are some of the
pertinent specs for the 2N1701.
NPN Silicon
Vcbo = 40V
Ic (max) = 2.5A
Pd = 25W
Hfe = 20-80 @ 300ma/4V
Vsat = 1.5V @ Ic=300ma, Ib=30ua
Iceo = 750ua @ 60V
Ft = 350KHz
Dave M
masondg44 at comcast dot net
I would not use a "cheap" general replacement transistor in a direct
coupled
unit unless it was absolutely positively the last one on earth. Many
vendors
have that 2N1701 in stock from 7 to 8 bucks American. We have repaired
thousands (no exaggeration) of units that all that was wrong is where
incompetent technicians used general replacement transistors rather than
the
originals in direct coupled amplifiers.
http://store.americanmicrosemiconductor.com/2n1701.html
Phil
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
