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Foxhunter
Junior Member
Username: Foxhunter
Post Number: 27
Registered: 4-2008
| | Posted on Saturday, July 05, 2008 - 12:48 am: | 
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I am trying to figure a possible combination of what I have already in terms of existing power supplies here at home for mobile amplifiers.
The mobile amplifiers I currently own and plan on using here at home are Texas Star's DX 500V and DX 350HDV, a (original/tube) Palomar 310M and a 2x SD1446 Fatboy. As you can see they range in output from 280W-500W +/-.
I just got a Pyramid PS52XK power supply and it can power the the amps I have EXCEPT the DX 500V as the amp just clicks and it's button/switches flash.
What I was wondering was can I combine power sources that are different to get a combined total? I've read if I parallel power supplies such as the Pyramid there they have to be EXACTLY the same in amperage or there will be problems. Is that exactly true?? I can't parallel a Pyramid PS 46XK together with a PS 52XK without suffering ill effects or causing damage to something?? They are fairly close in amperage but not the same.
Would I be better off (to get higher amperage) to use 2 sealed (to prevent outgassing) batteries and a battery charger together instead ?? Would that give me "AC hum" in the radio system as a result ?? Could I combine the Pyramid with the batteries and charger somehow ??
Am I better of doing something else altogether different ? I am trying to use what I already have and can't go out and buy a really large power supply at this time. I've never had a base station set-up yet and am working on getting one together as I am going to be around home for a little while my Mom is here dying with terminal illness and I am trying to care for her. Trying to work with what I got pretty much. Any ideas or suggestions?? |
Tech237
Moderator
Username: Tech237
Post Number: 1021
Registered: 4-2004
| | Posted on Saturday, July 05, 2008 - 12:17 pm: |
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The answer is Yes if you try to parallel unlike supplies you CAN have problems. Note the can. It depends on the design and circuitry of the supply, if you have a balance network involved.
Use the two gel cells and charger. Right now I have two gel cells in my shakc with their own charging system. These are wired thru a rely so that I use the 30A supply until I lose AC and then the relay drops out switching to battery power. In you case you would just wire them directly to the amp and have a float charger across them. If the charger is well designed you will get very little, if any, AC hum, and if you do it is simply a matter of adding a very large capacitor across the feed to the radio or even try a in-line filter.
Simon
Tech237
N7AUS
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 4321
Registered: 7-2004
| | Posted on Saturday, July 05, 2008 - 12:55 pm: |
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not good to hear about your mom, but always good to hear about you looking after her.
as for your power supply issues, the 52amp pyramid should power the dx500, possibly not full power, but it should be able to power it to nealry 400 watts PEP if not more. are you overdriving it maybe? if nothing else, you should see 250+ PEP from the dx350, which will have minimally less signal then the dx500. i'd check out the dx500 install 1st though, the 52 should run it. as for putting the 46 & 52 together, you need the same voltage, and theoretically, you should have different cable lengths and/or wire guages because there will still be different voltage drops due to different current amounts. 46 & 52 amps together, with barely 50 amp draw? shouldn't cause a problem, but you may want to check this out 1st, because it explains why you shouldn't combine those 2 supplies. it's for switching PS's, the 46 & 52 are not, but same principles apply. http://www.weidmuller.com/downloads/pdfs/ca_applNotes/PS06_Parallel_Operation_of_Switchmode_Power_Supplies.pdf
as for batteries & charger? not really the safest way to do it, but i have set up 4 systems like that, including 3 with dx1600's. both systems used dual optima batteries with 150 or 200 amp boost/chargers, they usually sat on low charge/30 amps when used a lot-for dxing say-hit 'high' when in heavy use, but never on boost. you want highest boost charger to get highest 'regular charge' rate available. you won't get full power out, but 800-900 watts in a base is good! 2 batteries 2 help keep voltage drop to a minimum, but it will still happen. 1 set up was 'outside' the house, others were in basements & set up with outside ventilation & separated from shack/living areas. |
Foxhunter
Junior Member
Username: Foxhunter
Post Number: 28
Registered: 4-2008
| | Posted on Saturday, July 05, 2008 - 11:22 pm: |
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Thank you Tech237 and Patzerozero for you much needed input I haven't been thinking as clearly and on top of that really need the advice. You guys have come thru before for me and I appreciate it more than you may think.
That Pyramid PS 52XK is rated at 46Amps continuous and 52Amps surge/peak. When the 500V amplifier was demonstrated at the time of purchase I was told (and believed) that it was not enough amps from the supply to operate the amp (hence the clicking and flashing) as the 500V is rated at 45Amps draw. I really don't like buying used amplifiers because it/they may have other problems that I'm unaware of but I do know that my power supply is "borderline-adequate" for this amplifer on high-power (like a dummy I didn't ask for it to be demonstrated on low-power).
Although I have always had mobile systems now unfortunately is the time for a first base set-up and although it won't be a "dream station" by any means I'd hate to install it at "bare minimums" and atleast want to have more than minimum power on reserve/supply if at all possible with what I have or can find affordable. I am looking at a funeral and burial soon for my Mom and caring for her has been terribly difficult and disheartening.
I may seriously try the 2 or more batteries with a decent charger attached as you guys were saying. Do the batteries have to ALL be the same as well? Float charger? Never did really know what the term meant exactly are you referring to the smaller "workbench/desktop" type battery chargers/maintainers? I have two of them and a larger Sears Craftsman one with wheels in the garage. Not sure which would be best, the one with the most power?
I have 3x large capacitors from my previous mobile set-up that I could employ each is One Farad or larger for AC hum/filtering.
What type of relay was used in the two-battery power supply configuration that Tech was mentioning?
Thanks for the Weidmuller link I found it useful and saved it to my favorites as well as printed it out for my radio/amp hardcopies as well. Anything else to add by either of you guys would be more than welcome I was getting desparate and thinking about using a really high-speed & torque industrial fan motor I have and hooking it up to two spare 90Amp alternators I have in my garage I thought it might work with the use of smaller "undrdrive" type pullies to increase the alternator RPM turns ratio for near full output. Until I can get thru this difficult time then maybe I'll try to get the proper hardware/components for a 1st Class station. If you have anything to add let me know please. Thanks------Foxhunter |
Tech237
Moderator
Username: Tech237
Post Number: 1023
Registered: 4-2004
| | Posted on Sunday, July 06, 2008 - 12:17 pm: |
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A float charger runs a low current (typically less then 2 Amps) at all times into the batteries, thus keeping the batteries topped up.The one I have trickles or floats at 2A and kicks up to approx 6A if the batter voltage drops appreciably (well once power is restored).
As for the relya I used a 12v headlight relay (rated at 30A on each of it's two sets of contacts). Wired the contact in parallel for increased current capacity. I wired it so that the batteries connected to the normal closed contacts (when no power applied to coil), the power supply went to the normally open ones as well as to the coil. This way, when the PSU is on, the relay is activated and switches the radios to the psu output. If the supply fails, the relay releases and the batteries now power the radios.
Hope that helps a little, if not post here and I'll sketch up a diagram.
Simon
Tech237
N7AUS
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Hotwire
Senior Member
Username: Hotwire
Post Number: 2542
Registered: 1-2005
| | Posted on Sunday, July 06, 2008 - 2:55 pm: |
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The PS52XK will run the DX500.
Sounds like a grounding problem. Your getting rf back into places you don't want it. Ground the power supply housing and it should go away. I had the same problem you describe with the same amp and power supply.
Is the electrical outlet your using grounded? Mine was not, only 2 prongs no third ground prong. If I was a bettin man I bet your house wiring is old style, no grounds on the outlets.
KEEP IT REAL!
Kenny
cef491(27.115lsb)
2sf491(27.555usb)
Indiana
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Foxhunter
Junior Member
Username: Foxhunter
Post Number: 32
Registered: 4-2008
| | Posted on Wednesday, July 09, 2008 - 10:14 pm: |
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Once again---Tech237, Pat Z and Hotwire, you guys are life-savers. I'm indebted to you and your explanative input I needed it. I'm getting "bad vibes" about using dissimilar power supplies as with my luck I can see something costly going wrong. I probably will try the 2 Optima's with a float-charger.
Tech237 I could use the diagram if you would, I really like the idea it's clever and will help me make what I already have work. If you can please post.
Hotwire I'm unsure why the PS52XK won't power the 500V It did the 350HDV perfectly using the same house outlet and neither amp is externally grounded but will be in the near future. Perhaps it is too "borderline" as far as supplying the amps that the 500V requires and it may work on the lower power setting that Pat had mentioned. Although you said you operated it with success using the same supply and amp. |
Hotwire
Senior Member
Username: Hotwire
Post Number: 2546
Registered: 1-2005
| | Posted on Friday, July 11, 2008 - 11:53 am: |
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When I use AM mode the DX500 works really well with the Pyramid 52. In SSB mode the power supply will max out and if I continue the abuse the power supply protection circuit will trip and then once it cools down I can reset it.
The DX500 will work with the PS52 I promise. In AM mode with about a 2 watt deadkey and 30 to 40 watt swing.
Obviously a deadkey needs less amps than the swing so if the power supply is doing its clicking problem with only a deadkey it is most likely an RF grounding issue. Sure the Texas Star 350 works fine but it is only putting out half the RF as the DX500.
Another tip, use a dedicated outlet. An outlet with its own circuit breaker. The power supply does not want to share with other appliances. I could tell a big difference when I did this. No more lights dimming in the radio room. Also keep all your coaxes and cables neat an organized. No crisscrossed cables and coaxes.All the little things add up to more better performance.
KEEP IT REAL!
Kenny
cef491(27.115lsb)
2sf491(27.555usb)
Indiana
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Foxhunter
Junior Member
Username: Foxhunter
Post Number: 38
Registered: 4-2008
| | Posted on Friday, July 11, 2008 - 11:17 pm: |
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I'll be clearing out a small neat storage room and be running additional heavy-amp house wiring pretty soon. My Mom just died this morning and I will have quite a number of things to be doing. I will be working on a proper radio room over the next couple months. I will do a nice neat install with more-than-adequate infrastructure as I can afford it as I will begin financially recovering I hope.
The "flashing and clicking" is coming from the Texas Star 500V---and not the PS52XK. The amp's switch lights all flash and click when I keyed up and I am wondering if this is a problem with the 500V itself now and not the supply. I was told from the seller that was the problem and when I looked at the 500V's draw listings on the spec's charts it confirmed it for me as the PS52XK only had one more additional ampere available than what the amplifer requires. I haven't used the amplifier since and will have to see what it does when properly set-up in my first base/home shack. I'm worrying now that I have a 500V problem instead maybe.... |
