[time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.

[Mark Spencer]

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
mark at alignedsolutions.com
604 762 4099

> On Sep 24, 2020, at 3:30 PM, Bob kb8tq <kb8tq at n1k.org> 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 <mark at alignedsolutions.com> 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
>> mark at alignedsolutions.com
>> 604 762 4099
>> 
>>> On Sep 24, 2020, at 12:38 PM, Magnus Danielson <magnus@