Astron 35M + UPS?

[KE4ZDY]

Does anyone have any experience or recommendations regarding the use of a large capacity UPS (unmodified!)to power an Astron 35M (that powers a IC-746)?

I have an opportunity to pick up an APC "Smart-UPS" (pure sine) UPS in the 1000 VA range (or maybe a bit more). Are there any reasons why this would NOT be a good way to operate?

Any evidence (circumstantial or otherwise) such as "stray RF causes the UPS to lose regulation" might be interesting.

Thanks!
Gerry

[OBSERVER11]

go read the elmers section, there is a question about RF in an Astron right now...

YES, RF will effect the regulation of the power supply.

The SmartUPS will power the supply, but there are better ways to do what you want. If you connect the power supply to the UPS and you loose power (mains), the UPS will pick up the load, but the power supply is inefficent to start with, running off a UPS only compounds the issue.

[WA4MJF]

I use APC UPSs on Astron supplies for
critical equipment.  However, from
power failure to generator on is
only about 30 seconds.  So I've had no
problems.  I guess the question is how
long are you planing to let the UPS
rune the Astron PS.

73 de Ronnie
OBS/OES

[KE4ZDY]

OBSERVER:

Thanks for the pointer to the Elmers append.

I do appreciate that the arrangement I've asked about is sub-optimal. I'm not (at this time anyway) concerned with operating indefinitely off-main. If my calcs are right, I think I could receive for 6-10 hours with this arrangement if it came to that (xmit times are clearly much shorter).

My main desire was to prevent surge/power cycle events from reaching the radio.

Thanks again,

Gerry

[KE4ZDY]

Ronnie:

Thanks also for your response.

I was more specific about why I asked the question in my response to OBSERVER. My goal is really to shield the radio from intermittant power events & power quality issues. Power line conditioners are usually targetted at industrial/commercial apps & therefore seem to be very expensive. Some of the better UPS products will give much the same protection but are priced more attractively.

I'm new at this forum stuff -- I really should have put more detail in the original post.

Rgds,

Gerry

[KB9YUR]

 Gerry,

 you'll have absolutely NO problems with the Astron 35M & the APC unit. I have the
 same set-up here, and it's been running fine to an Icom 746, 275H & 7100.
 The APC smart UPS units are specifically designed to produce a pure sine-wave
 output and also have the protection against blackouts, brownouts and AC line noise.
 In fact, our larger APC SU2200 XLNET unit actually provides backup power to the
 entire house, especially the electric motors that are used in the baseboard hot water
 heating system. If you have the XLNET unit, you can also add additional external
 batteries for extended runtime. I've owned APC units since the early 90's, and
 never had one fail yet (though you'll need to replace the batteries from time to time).
 
 George ...

[KD5UJX]

Seems to me it would make more sense (money wise) to buy a 12V storage battery and a large (30amp) automatic charger.  If there is RFI from the charger, just turn it off!  I am running this setup in combination with solar pannels.  That way I can run "off the grid" for severl days.

[KE4ZDY]

George:

Thanks for sharing your experience. This is exactly the sort of info I was hoping for!

Gerry

[KE4ZDY]

William:

Strategically, I think I would like to follow your lead. Your solution: multiple sources (substantial charger, solar panels) feeding through a fairly massive buffer (the battery) would give me relatively clean power at the radio with brownout protection and long, off-grid run times. I agree that this may have more utility (pun intended) for less money than my approach. Unfortunately, my shack accommodations won't tolerate that solution right now, dern it.  

Thanks,

Gerry

[K2GW]

I'm assuming you're talking about a linear Astron 35M.  If so, consider just using the power supply to power a RigRunner distribution strip and float a large gel cell across it.  Here's something I submitted to Hints & Kinks but was never published.  I've been running my station this way for about 18 months.  My radios work for a few hours even with no AC.

It was nice to see the RIGrunner 12 VDC distribution panels featured in the October “Short Takes” and the 30 amp Anderson Powerpoles promoted in the November QRP column.  Besides being able to share equipment, power supplies and batteries with other hams, using this standard 12VDC ARES/RACES connector makes moving equipment in your home shack much easier as well.  

I recently discovered that powering my home station through a RIGrunner makes adding a large gelcel battery for automatic back-up power very easy.  In his series of classic article on standby battery power (QST March to May, 1990; available on the ARRL website under the TIS/Emergency Power selection)) W4MLE shows that a gel cell battery can be safely floated across a regulated 13.8 VDC power supply for battery back up.  Since all of the outputs on a RIGrunner are individually fused and can also be used as inputs, it’s easy to have a regulated power supply and a gel gel connected to power bus simultaneously.  This not only allows operations when AC power disrupted, it also allows the battery to provide power for peak loads, assist in surge protection and filter any residual ripple from the power supply.

To do this, I simply plugged my Astron RS-35 35 amp 13.8 VDC power supply into the RIGrunner input position using a 35-amp fuse.  I then connected my 85 amp-hour gelcel to position 2 of the RIGrunner using a 40-amp fuse in that position.

As W4MLE mentions in his sidebar in the April 1990 QST, your power supply might need to be protected from reverse current flow when AC power is lost.  Installing a hefty diode in the supply line from the power supply is one way to do this.  

If you use the popular Astron line of linear power supplies, it’s even easier.  They use a 723 IC for regulation.  Adding a ½ watt 10K ohm resistor between pin 4 of the IC and the wiper of the voltage adjust potentiometer restricts the current flow to protect the IC.  To do this, merely disconnect the power supply from everything, open the case and locate the “L” shaped trace between pin 4 of the IC and the wiper of R5.  Cut the trace on the circuit board with a Dremel tool or Xacto knife and bridge the gap with the 10 K ohm resistor.  More details and circuit diagram can be found at www.ntc.cap.gov/comm/ntc/rs35amod.cfm

As is mentioned, a fuse is also needed between the power supply and the battery to protect the SCR’s if the crowbar circuit ever fires.  The fuses on the RIGrunner automatically perform this function for you!

So I now have automatic standby power, improved surge protection, peak load supply and better filtering all for the cost of 10K ohm resistor!

Thanks to Michael Tracy, KC1SX at league headquarters for his help with this.

73
Gary Wilson, K2GW
Section Emergency Coordinator
Southern New Jersey Section

[WA9SVD]

Well, it seems quite inefficient to use DC to convert to AC to power a linear supply to supply a radio that runs off DC.  The battery power could probably be used much more efficiently to power the radio directly.
    But a UPS in the 1000 W. range probably operates on other than 12 VDC, meaning "gel cells" in series.  So a charging system might have to be devised.

    One of my concerns or questions is how long the UPS systems can provide power, if provided with unlimited DC of the proper (battery) voltage?  Can the UPS operate continuously for a relatively long time (such as having additional deep charge batteries connected to provide long-term operation) or are the UPS circuits designed to operate only for a specified period of time without overheating or overload?

[KB9YUR]

 The APC SU2200XLNET UPS model we use here can operate for several days (maybe
 even a week) only on batteries depending on the load to the system. It will not
 overheat because there's a heavy duty industrial fan inside the unit. Don't forget that
 most of the larger UPS units (including APC) are designed not only to operate 100%
 trouble free in IT installations, but also in the military as well.

[WB7TDG]

I am using a Cyberpower PR3000SWRM2U UPS, a sine wave corporate size unit,  that is capable of running 30 amp 120 vac to feed a pair of Astron 35 amp power supplies for my radio station plus a desktop pc. Have this system up and running for over a year now without any problems.
I set the UPS up in the basement with two banks of 4 each 38 amp hr Hawker AGM batteries. This particular UPS specifies AGM batteries rather than gel cells.
I then ran a romix 12-2 line to a dedicated a/c wall socket in the shack on the main floor.
I also made a Farday shield...some aluminum window screening that surrounds the UPS and connected to a ground rod in the basement to keep the inverter hash from getting into the hf station.
I also have a 30 amp breaker box on the output of the UPS. This system is also on a dedicated input a/c circut line from the main household breaker box.
Power transfer is seamless when the lights go out and the UPS keeps the AGM batteries charged well within specs of float charge of the batteries.
Hope this helps someone a bit.