[Boatanchors] OT: The DC battery system for my ":shack" (long monologue)

Wed Jun 15 17:36:07 EDT 2016

Hey Phil - that Astron 50 will make a great shack heater in the winter.

They generate an enormous amount of heat.  It feels like what you used to get from a BC610 !!!
Even when idling....
> To: boatanchors at mailman.qth.net
> From: ko6bb1 at gmail.com
> Date: Wed, 15 Jun 2016 21:17:05 +0000
> Subject: [Boatanchors] OT: The DC battery system for my ":shack" (long	monologue)
> 
> Hi,
> 
> OT for this list, but then the Astron 50A supply qualifies as a 
> "boatanchor" at ~48lbs!
> 
> Just thought some of you might be interested in how I power nearly ALL 
> equipment here, or at least anything that runs on 12 Volts.  That 
> basically includes everything but the computer equipment and the 
> homebrewed tube type regen.
> 
> The PRIMARY power source is an Astron RS-20M (metered) 13.6V power 
> supply that's tied into the main DC power buss under the operating 
> bench.  The 24/7 'standby' power draw on the supply runs about a 
> conservative 5 Amps.  The "On 24/7 equipment is typically the TYT dual 
> band Xceiver, Icom IC-7200 Xceiver, 4 port multicoupler, DSL Modem & 
> router, float-charging the battery bank.  In addition during operations 
> (such as a CLE) the R-75, Icom IC-735, Pre-amp/control center, Softrock 
> system etc may all be left on all weekend, running the 'standby' current 
> up to about 8 Amps (still almost conservative for the PS).
> 
> Also tied into the 12VDC system is a 300W 110VAC inverter that can let 
> me have a small amount of AC during a power failure for items such as a 
> fan on a hot day, computer etc.
> 
> BUT, IF I transmit on any of the Xceivers with most of the auxiliary 
> equipment turned on the the PS Ammeter pegs hard at >20 Amps (it IS 
> supposed to be current limited, but I've never tested it to see what 
> that limit is).  On the Astron supplies, the model# number indicates the 
> intermittent current rating and they should NEVER be operated 24/7 at 
> more than half of that rating!!!  To do so invites disaster.
> 
> My Astron has been running just fine for well over 15 years now, but as 
> I've added more equipment it does seem to run somewhat warmer, though 
> not excessively so.  THAT IS, unless there is an extended power outage 
> and the supply has to bring the battery bank back up to full charge!  
> Then the supply gets pretty warm (even with the muffin fan I put on the 
> heatsink).
> 
> In any case, I wanted to get a larger supply and it was on my list of 
> "future things to do".
> 
> Well, last Saturday, at the usual Saturday Ham Radio "Coffee Klatch" at 
> the mall one of the old timers asked me if I'd repair an Astron 50 amp 
> (linear) power supply for him.  Said he has two needing repair, IF I 
> fixed one for him I could have the other.  One has meters, one not, he 
> wants to keep the metered one.  I told him sure and dragged the 
> unmetered one he'd brought home (they weigh ~48 lbs each).
> 
> Checking it out I found that it put out 13.6VDC, BUT had a lot of ripple 
> and noise on the DC output.  I pulled ALL 8 of the pass transistors 
> (known to fail).  They tested good so I re-greased them and put them 
> back in. Further troubleshooting turned up an open emitter equalizing 
> resistor on one of the pass transistors, but all that'd do is reduce the 
> current capacity by about 1/8th.
> 
> Further troubleshooting showed ripple and noise on the output of the 
> LM723 regulator chip.  Hmmm, found that the 'lytic capacitors on the 
> main board were all dried out,and in fact the 2200uF capacitor in the 
> (low current) PS for the regulator itself was open (a separate supply 
> from the main humongous filter capacitors of the main circuit).  
> Replaced ALL the small 'lytic capacitors on the board (4), found one 
> lead on the 2200uF cap was burnt open, rechecked PS.  VOILA!  It works 
> as it should! Still need to replace that one open resistor to restore 
> the 8th Pass transistor in the circuit (each of the 8 pass Xistors has 
> an .05 Ohm 5W equalizing resistor in the emitter).
> 
> At this point, since this is an 'early' Astron (1984 date codes) I went 
> ahead and did the recommended upgrades to it, including adding the 
> protective resistor that protects the LM723 IC when used with a 
> "float-charged" battery bank (after all, this will be 'my' supply when 
> I've finished the 2nd one.
> 
> **************************************
> 
> Since this Astron is the one that doesn't have Voltage/Current meters, 
> AFTER it's mine I intend to add metering to it, and will use a digital 
> meter to display Voltage, Current, Watts and accumulated "energy".  
> Don't need the last feature, but I liked this particular meter MUCH 
> better than the ones that only showed Voltge/current.  I'll put the 100A 
> current shunt INSIDE the Astron and Velcro the meter to the front face.  
> There's enough room inside for the shunt. I ordered the needed .05 Ohm 5 
> Watt resistors for the PS AND the meter etc just this morning.  But 
> won't install the meter until I've confirmed that I can repair the other 
> unit (I'm sure I can) and that this one is mine. . .
> 
> I ordered this meter (with 100A shunt).
> 
> https://www.amazon.com/gp/product/B013PKYILS/ref=od_aui_detailpages00?ie=UTF8&psc=1
> 
> 
> *******************************
> 
> Change of subject.
> 
> *****************************
> 
> I've long been wanting to wire in a "disconnect switch" between the PS 
> and the rest of the DC Buss circuitry (I.E. the Heavy DC fuse-blocks 
> under the bench, the heavy (it's either 4ga or 6ga) DC cable going to 
> the battery bank in the shed just the other side of the outside wall and 
> so forth.  Since we're talking heavy currents and relatively low 
> Voltages (13.6V), even a small Voltage drop would effect overall system 
> effectiveness.  I'd considered a really heavy relay on the output of the 
> PS that would drop open when the AC power fails (or is turned off).
> 
> I would be just as happy to be able to manually disconnect the PS from 
> the rest of the system.  Then I ran across this behemoth of a DC switch, 
> rated 275 Amps continuous, 475 Amps intermittent!!!  Designed for Marine 
> and RV service it should do the job.  In fact, IF I like it well enough 
> I'll probably get a 2nd one to use in the DC cable going to the battery 
> bank.  Make it easy to disconnect the battery system when servicing them 
> (right now I just remove one of the big-honkin' fuses to do that.
> 
> Here is the switch. The funny thing is, I wasn't looking for it at all, 
> but while looking for the volt/ammeter it popped up as a "related item". 
> Which led me on a search for switches.  This one, while not the cheapest 
> one on Amazon, looked like about the best for the price (you can spend 
> well over $100 for a battery disconnect switch).
> 
> https://www.amazon.com/gp/product/B005DUUL9W/ref=od_aui_detailpages00?ie=UTF8&psc=1 
> 
> 
> Comments, suggestions?
> 
> 
> -- 
> 73 From "The Beaconeer's Lair"
> Phil, KO6BB
> http://www.qsl.net/ko6bb/  (Web Page)
> 
> HF/LF RADIOS:
> Grundigs: S-350 (~2006), G6 (2011) & S450DLX (2014).
> HOMEBREW: 7 Tube+Rect 1v3 Regenerative RX for LF (built 2015)
> Icom:     IC-735 Transceiver (~1990).
> Icom:     R-75, Cascaded 250/125Hz CW-Filt, Panadapter. (~2009)
> Icom:     IC-7200 Transceiver (~2015).
> R-Shack:  DX-380 digital portable (~1990).
> SDR:      Softrock Ensemble II LF (built from a kit 2015).
> Zenith:   Royal-7000 Transoceanic Portable (~1968).
> 
> ACC:   HOMEBREW  LF-MF Pre-Amp, MFJ-993B HF Auto-Tuner.
>         HOMEBREW  4 Port Multicoupler, Feeds Antenna to 4 RX's.
>         HOMEBREW  8 Hz Audio Filter.
>         Timewave  DSP-599zx Audio Filter.
>         Behringer 1202fx Audio Mixer (for mixing/routing audio).
> 
> ANTENNAS: 88 foot Long Ladder-line fed dipole, 35 feet AGL for MW/SW.
>            Active Mini-Whip, 36 Feet AGL for LF/MW/SW.
>            37 foot "Low Noise Vertical", 11 feet AGL for LF/MW/SW.
> 
> Merced, Central California, 37, 18, 37N   120, 30, 6W CM97rh
> 
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