Thanks Bob that is helpful. The external regulator approach you mention was the direction I was headed in for powering the BVA, but I realized that I would need more than 24 volts into a simple linear regulator to get a stable 24 volt output which complicated using my existing 24 volt battery system.
Maybe I am over thinking this. For now I run the BVA as needed from a lab supply that is powered by a UPS. A better backup scheme is something else to look at down the road as I get back into the time nuts hobby. I really appreciate my FTS1050 and HP105B with their separate AC and DC power connections in this regard. Mark Spencer [email protected] 604 762 4099 > On Sep 24, 2020, at 3:30 PM, Bob kb8tq <[email protected]> wrote: > > Hi > > Maximize life = put it on the shelf and *never* power it up. It (may) last > for a century that way. > How you will *know* it’s still doing fine is very unclear. > > Maximize utility = power it up and keep it on power all the time. If you can > plan well, power it > up 9 months before you need to use it. > > There is a lot of data suggesting that > 90 days of stabilization is a good > idea on OCXO’s. > That’s based on fairly basic parts. On something fancy, it’s a good bet that > even longer is better. > > === > > Does it need to be on power at 24V +/- 0.00000001 V for 9 months ahead of > time? Is a 1 hour > power outage 3 months back a really big deal? Both are in the “that depends” > category. > Good bet is “don’t worry about it.” > > One practical approach is to mount a regulator external to (and thermally > isolated from) the > OCXO. Then apply whatever supply you happen to have. Net result is that the > device does > not see any crazy voltage spikes. A diode “voting” setup could also be > integrated into the > regulator board. > > Bob > >> On Sep 24, 2020, at 4:47 PM, Mark Spencer <[email protected]> wrote: >> >> Hi All. I have a related question.. >> >> From a maximizing the life span of the BVA perspective if one only wants to >> use it once a year or so and can wait for a month or so for it to stabilize, >> does it make more sense to mostly leave it powered down or is leaving it >> running all the time a better plan ? I realize this type of question may >> not have an definitive answer but I am curious about the views of others. >> >> I have a couple of other OCXO's that I leave running all the time and have >> never quite gotten around to putting together a guaranteed to never go down >> DC supply for my BVA. My read on the voltage specs for my BVA discouraged >> me from simply powering it from my 24 volt DC battery bank that is float >> charged at a somewhat higher voltage when AC power is available. >> >> Given the typical price of a BVA, I don't have a spare BVA in my time lab >> and would like to maximize its life. Over the years several other pieces of >> gear have failed but I have spares for them (: >> >> Thanks in advance for any comments. >> >> Mark Spencer >> [email protected] >> 604 762 4099 >> >>> On Sep 24, 2020, at 12:38 PM, Magnus Danielson <magnus@ _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
