[time-nuts] Z3816 Oscillator Saga
Chris
syseng.greenfield at btconnect.com
Tue Apr 29 23:07:27 UTC 2014
I seem to have painted myself into a corner with a Z3816 and wonder if
anyone can help. Originally bought from Ebay US over 5 years ago and
used since to drive several items of test gear and an hf receiver. It's
the ac line model and the only mod was to fit a small fan to keep the
insides cool.
Over the past year or so, the efc started to get noisy, spikes on the
plot, which settled down if the box was moved, or given a tap. Assumed
that the oscillator had a dry joint internally, so decided to replace
it.. Initially carefully unsoldering the existing oscillator, refitting
with thin slice of polystyrene at the pins to isolate the heat from the
board, but no change in the efc after a few weeks. Removed it again, but
the pliers used to loosen the pins on the pcb (after solder sucking)
slipped and damaged a couple of sm caps and resistors at the sma
connector end of the board. No idea what value these were, so can't
replace. The original oscillator was an MTI 260-0558, while the
replacement is an MTI 260-0624. Needless to say, it fails to lock with
the replacement, but because of the board damage, not clear if this is
due to incompatable efc range, or due to missing (damaged) parts.
Meantime, also carefully opened up the original oscillator, but nothing
obvious and that now doesn't lock up either, so perhaps best to stop
digging.
Ideally, I would like to find another Z3816, as this would provide a
spare as well as visual id of damaged parts to allow repair, but haven't
seen any for sale recently. The other point is that the unit (replaced
oscillator) doesn't seem to do a search through the whole efc range, but
always seems to go back to the setting for the original oscillator. Some
way of resetting this to search mode would be helpful, but again, no
info, or schematic. Have found the cpu reset pins on the dil header from
the cpu data sheet, which does save some gps init time on a restart, but
not clear what the other pins are for.
Any ideas ?. It's been a great lab standard and it would be good to keep
it running for a few more years...
Regards,
Chris
More information about the Time-nuts_lists.febo.com
mailing list