[time-nuts] 5370A vs 5370B
jmiles at pop.net
Wed Mar 10 01:20:19 UTC 2010
> The display rate pots is particularly useless. You can just
> hardwire it to max.
The only case I've seen where that's an issue is when using the counter over
GPIB, free running in talk-only mode. If I run it with the Prologix
Ethernet adapter, which turns each reading into its own TCP/IP packet, I
have to back the display rate down to about 1/2 maximum to let the adapter
keep up. Not a huge deal, and it probably wouldn't be a problem with
non-Ethernet adapters at all.
> The biggest bugaboo in buying a 5370 is the state of the HP
> custom input amplifier chips. They can be damaged by overloading
> the input. Blow one and you are screwed. Buy a 5370 with a
> blown input amp and you are screwed. The 5370A and 5370B used
> different chips. The 5345A counter is a source of input amp chips.
Hopefully Demian won't keep us in suspense re: that Maxim part...?
> It would be VERY nice if some clever person built drop in
> replacement "chips" built of modern SMD parts on a DIP header.
> Those input amp chips are socketed. They are little more than a
> Quick check of the 5370A inputs is to set the unit to "SEParate"
> inputs and connect the back panel 10 MHz ref signal to each of
> the inputs. The signal level LED should flash. A steady LED
> means that input is toast (or the input PCB slide switches are
> full of navel lint and need cleaning).
The switches are indeed a reliability problem. They're about as well
thought-out as the pots you mentioned.
-- john, KE5FX
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