[time-nuts] HP 106B quartz frequency standard...the story

Ed Palmer ed_palmer at sasktel.net
Tue Aug 11 03:16:52 UTC 2009


FYI, there's a seller on eBay selling two 2N1701 TO8 NOS transistors for 
US$20.  Looks like he'll do first class mail for shipping.  Item # is 
250025584633 .

Ed

Jim Palfreyman wrote:
> 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 <fortime at bellsouth.net>:
>   
>> ----- Original Message ----- From: "Dave M" <masondg44 at comcast.net>
>> To: <time-nuts at 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 <masondg44 at 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
>>
>>     
>



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