[Premium-Rx] Fw: SV: Further DRO-333 Stuff

[Terry O']

My understanding is that even when they were factory fresh the UHF tuner 
was prone to waltzing.  Small temperature changes altered dimensions at 
0.5-1 GHz enough to notably affect performance.

About 4 years ago I interviewed one of the main techs who aligned these 
radios before they shipped.  The alignment procedure in the book is the 
rough outline.  The factory alignment procedure was much more 
complicated.  The difference was not unlike taking a Mustang GT350 to 
Sears Auto versus taking it to Carroll Shelby (RIP).

Terry O'



On 1/13/2014 12:20 PM, David Schofield wrote:
> Hi Everyone,
>
> Just to confirm that the 74LS196 definitely works in place of the N8292A, in location U6 anyway, this is a reasonably low speed part of the circuit though, so I can't vouch for equivalence in other designs.
>
> The good news is that my DRO-333A is now counting away happily again, but more importantly the DAFC output is holding the RS-111-B-12 on frequency making it usable again.
>
> Does anyone know if all of the RS-111-B-12 receivers drift wildly for several hours before showing any sort of stability, or out of interest, do I have a problem with the receiver as well.
>
> Cheers,
> Dave. S.
>
>
> Peter Ratuschni <zpz at gmx.de> wrote:Hi,
> to summarize the replacement types for Signetics counter ICs I have seen inside the wj DRO-311 and 333:
> 8280N - Presetable BCD-Counter / NS8680N =SN74176
> 8290A - Presetable BCD-Counter, Highspeed=SN74196, 74S196?
> 8292A - Presetable BCD-Counter, Low Power=SN74LS196 (number used in DRO-333: 18)
> 8293N - Presetable Binary Counter, Low P.=SN74LS197
> It looks that the situation for replacement of these is better than with some ECL ICs or with some of the
> 74 TTL series itself, especially when it comes to memory types. I.e. if you are looking for a 7489 you have
> to look for the russian comparison type KM155RU2.
>
> b.r.
> Peter
>
>> I have compared the datasheets for the two types, they look exactly the same, function- as well as pin-wise.
>> Haven't tried them, though, I have not seen many of the 82-series TTL family..
>