[time-nuts] Hp10811 parts ref

[Didier Juges]

The LM208 is a single op-amp with low offset (<3mV) and low bias current.
The NTE928 is a dual op-amp with <7mV offset. You may be able to live with
the offset at the cost of degraded performance but the pin-out is not
compatible.

Look for a single op-amp with very low offset. I am not near a computer
right now but there must be a ton of those at Digikey.

Didier KO4BB


On Wed, Sep 11, 2019, 9:21 AM Club Internet <clemgill at club-internet.fr>
wrote:

> Luciano,
> References of the manual is the following:
> MANUAL PART NUMBER 10811-90002 Microfiche Part Number 10811-90003
> Dated August 1980.
>
> Thanks very much for your reply (indeed npn and Q6...!)
> Looking for a replacement for UA208 (obsolete) hard to find, as well as
> LM208 => would NTE928 or ECG928 be ok ?
>
> Best,
> Gilles.
>
> Envoyé de mon iPad
>
> > Le 10 sept. 2019 à 20:29, "timeok at timeok.it" <timeok at timeok.it> a écrit
> :
> >
> >
> >   Gilles,
> >
> >   what manual you refer? (Part number)
> >
> >   Heating transistor are NPN.TO220 similar to TIP120
> >
> >   Driver is Q6 and NPN similar to 2N3904
> >
> >   U1 is LM2904N
> >
> >   U3 is uA208M
> >
> >   Luciano
> >
> >
> >   Da "time-nuts" time-nuts-bounces at lists.febo.com
> >   A time-nuts at lists.febo.com
> >   Cc
> >   Data Tue, 10 Sep 2019 17:54:17 +0200
> >   Oggetto [time-nuts] Hp10811 parts ref
> >   Dear list,
> >   Looking forward to apply the oven configuration of the 10811 oven
> oscillator - that is working so well - could you please help me identifying
> the appropriate references for the active parts :
> >   Q7 and Q8 heating darligntons PNP
> >   Q4 driving transistor PNP
> >   U1 and U3 op amps
> >   From the schematic on fig 8-15 on page 64 of the HP manual.
> >
> >   Thx very much,
> >   Gilles.
> >
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