Power supply...

[K9CCH]

Back in the day, when we were 13 or 14, the group of neighborhood kids all got CB radios. I assume it was because one kids dad is a ham, and he had his dads CB set up in his room. Anyway, I bought this with lawn mowing money, and hooked up my dads old Uniden that he had installed in the 1979 Chevy Monte Carlo. It currently has cigarette lighter adapters hooked up, but I'm going to pull those off.

Can I use it to power the FTM-350 that I picked up? I'm assuming that because its 40w max, I won't be able to use the radio at full power, correct?

[KJ3N]

Can I use it to power the FTM-350 that I picked up? I'm assuming that because its 40w max, I won't be able to use the radio at full power, correct?

You'll be lucky to be able to use the FTM-350 at its lowest power setting. That power supply only delivers 1.75 amps. The radio is going to draw at least half that just sitting there.

The 40w rating is what is draws from the AC line. It's not what the power supply can supply to the radio.

[K9CCH]

So I should junk this then?

[KJ3N]

So I should junk this then?

You can run an HT with it. That's up to you.

An FTM-350 draws about 12 amps at full output. I'd suggest a supply rated for at least 15 amps.

[KC2UGV]

Don't junk it. It's useful for something, just not powering your rig.

You can look at converting an old PC power supply into a temp power supply for your rig. It should handle 10A on the 12V rails. Play it nice, and keep and eye on things, but it should work until you get a proper unit.

[K9CCH]

I'll order this when I order my mobile antenna then...

http://www.hamradio.com/detail.cfm?pid=H0-009793

[N8YX]

I'm going to be putting a used Astron RS35A up for sale for a fellow ham/widow as soon as I test it out. She's not looking to get the moon out of the thing, just a reasonable figure plus shipping.

That supply will more than handle a VHF rig and a most 12V HF rigs.

Let me know if interested.

[K9CCH]

Let me know what the price is...

[K7SGJ]

I'll order this when I order my mobile antenna then...

http://www.hamradio.com/detail.cfm?pid=H0-009793

I'd take Fred up on the Astron offer. I have several, and they are pretty much bomb proof. But if one should ever go TU on you, they are a cinch to fix.

[K9CCH]

I'd take Fred up on the Astron offer. I have several, and they are pretty much bomb proof. But if one should ever go TU on you, they are a cinch to fix.


Price is going to be key... I'm pretty much on a non-existent budget.

[N8YX]

There's currently a -20A floating around the 'Net for $60 and shipping. Assuming this thing load tests OK (no ripple, etc) make me an offer I won't refuse.

[K7SGJ]

Price is going to be key... I'm pretty much on a non-existent budget.

I hope it works out for you. One other thing to consider; some switching power supplies can generate a fair amount of noise do to the nature of the design. I think most of the ones designed to power radio equipment is pretty well filtered and suppressed. Also, at VHF/UHF, and especially FM, it may not be as much of a consideration as it would be at HF frequencies, and other modes. I have no knowledge about the one you were looking at, but maybe someone else has some direct knowledge they can pass along. You might even see if there are any equipment reviews, you might try to Google it or try Eham. The Astron is not a switching type supply, and that problem is non-existent. Just something to be aware of, and it might even be a non-issue. Just a heads up for you.

[K9CCH]

I know I have a few power supplies from some old laptops, and perhaps a speaker system. Is it as easy as cutting the connector off the end and connecting + and - and plugging it into the wall? Considering its the proper output etc...

[K7SGJ]

I know I have a few power supplies from some old laptops, and perhaps a speaker system. Is it as easy as cutting the connector off the end and connecting + and - and plugging it into the wall? Considering its the proper output etc...

Again, as someone else noted, you'll need at least 10+ amps@13.6 to properly run that rig. Most laptop supplies are 4 amps or less, and any more are around 19 volts. Some of the older ones were 15 or 16 volts at 2-3 amps, but again, they will be lacking for your application. I'd beat Fred up for a good deal on the Astron. It is heavier to ship than that other one you were looking at, but well worth it. And, if he checks it out and says it's good to go, you can bet the rent it is.

[KG4NEL]

I bought my RS20 used - it may have been the 2nd ham-related purchase I ever made.

12 years later, it's still chugging along...although on bench duty now. I'd snap up the RS35 in a heartbeat if I were in your situation.

[W7XF]

Chris....seriously, don't consider anything less than 12V 20A output. If your radio taxes your power supply to its limit, you will have a lot of AC hum on your signal. Whether you get a switching supply, or a transformer supply is totally up to you; however, a transformer-based supply may be rather costly to ship. I'd go over to Fry's Electronics..they have a reasonable selection, and they're well priced.

[KC2UGV]

I know I have a few power supplies from some old laptops, and perhaps a speaker system. Is it as easy as cutting the connector off the end and connecting + and - and plugging it into the wall? Considering its the proper output etc...

I should have been a bit clearer when I said a computer power supply. I mean the internal power supplies for desktop machines. The laptop bricks are noisy as fuck (I've tried them to run a small HF rig) and have some funky power protection circuits (To prevent overcharging and the like I presume) which cut out if you're not exactly matched to what they are expecting.

You can get the case power supplies for nearly nothing pretty often. Look on Craigslist and garbage piles for people tossing computers, and gut it. You can find the instructions for doing the required mods here: http://web2.murraystate.edu/andy.batts/ps/powersupply.htm

It's a nice project for a new ham, to get down and dirty with a soldering iron and components that wont burn up easy.

As for the Astron Fred is offering up for sale: Jump on it. Sell blood and sperm if needed (EW! Not mixed together). I have a 30 year old Astron still kicking, and it's what I'm running my station on at the moment.

[W3WN]

I'd take Fred up on the Astron offer. I have several, and they are pretty much bomb proof. But if one should ever go TU on you, they are a cinch to fix.Fred is a good guy, he'll make you a fair offer.

FWIW, a couple of years ago, I bought a working RS-35A at a hamfest for $35; it powered my TS-480SAT for a couple of years before that got traded for the Omni VI+. At present, the Astron is the backup to the Omni & Corsair power supplies...

I should be getting my 10 meter rig back fairly soon, and I should have a spare RS-7 once that happens. I suspect that won't be enough power for you, though.

[KB3LAZ]

I bought my RS20 used - it may have been the 2nd ham-related purchase I ever made.

12 years later, it's still chugging along...although on bench duty now. I'd snap up the RS35 in a heartbeat if I were in your situation.

Yep, they are worth the investment. A power supply was one of the first things I bought too. I have had my RS-70A for 9 years now and it was used when I got it. Hell, my grandfather has been using his RS-35A for likely my entire lifespan. Lol.

[W3WN]

Oh, I should add that I do not have a high opinion of those RS "Micronata" power supplies.

A club member donated one to run the NP2SH beacon. It malfucntioned and sent a spike into the beacon transmitter. Both were repaired, and then it happend a second time.

The beacon is now running on an Astron RS-7B that I got my hands on. (That's not a typo; the factory label said RS-7B, not RS-7A. No idea what the difference is, but outside of the label, it looks and works exactly like my spare RS-7A)

[wa6mhz]

You should indeed grab that Astron. I only trust my rigs on Astrons. It is foolish to put a several Hundred dollar radio on a junk power supply. With that Micronta, your greatest danger is popping the pass transistor which would put the raw DC Voltage on the radio OVER VOLTAGING it. Radios can survive Reverse polarity most of the time due to protection diodes. But overvoltage will COOK the internal circuitry, even a low current overvoltage.
I woudn't hook up that very nice FT-350 to anything but a good quality bulletproof Astron (which has Overvoltage Protection built in) and Current limiting.

[K9CCH]

Glad I asked.

we are in discussion on the Astron. I'm just trying to figure out how I'm going to finance the radio, power supply, and everything. My hobbies have to support themselves so I'm thinking I'm going to sell off a lens that I'm not using...

[WX7P]

Glad I asked.

we are in discussion on the Astron. I'm just trying to figure out how I'm going to finance the radio, power supply, and everything. My hobbies have to support themselves so I'm thinking I'm going to sell off a lens that I'm not using...

More overtime. that's the ticket

[K7SGJ]

Glad I asked.

we are in discussion on the Astron. I'm just trying to figure out how I'm going to finance the radio, power supply, and everything. My hobbies have to support themselves so I'm thinking I'm going to sell off a lens that I'm not using...

Are you sure you can get by with just one eye?

[K9CCH]

More overtime. that's the ticket



They BARELY pay me straight time. My little $14/hr public safety pay doesn't really give enough room for hobbies.

[W3WN]

Glad I asked.

we are in discussion on the Astron. I'm just trying to figure out how I'm going to finance the radio, power supply, and everything. My hobbies have to support themselves so I'm thinking I'm going to sell off a lens that I'm not using...Good! I'm sure you'll be able to work something out... and it will be well worth it.

Did you know that Kenwood used to OEM some of the Astron supplies for use with their HF rigs? Believe it... I used to sell them, back in the day. At the time, the RS-20A was $99 MSRP, the Kenwood version (KPS-20? I'm not recalling the exact model number offhand) $149. I could put the two side by side, the only difference was the side of the front panel that the power switch was mounted on. Yet people would buy the Kenwood version... think about that one. (And no, they didn't "match" the Kenwood HF rig du jour, which was the TS-430S... the official matching PS with speaker was $199 MSRP)

I've used Astron supplies since I owned a 430 back in the day... mid 1980's. I've had exactly two problems. Bridge rectifier blew in the first RS-20A, which I bought used... and may have been caused by my brother-in-law, which is another story. Replaced it, and the unit performed flawlessly until I disposed of it with the 430 (also another story). Second RS-20 (also got used, trade with W3SRL) ran multiple rigs over about 15 years. It was powered on almost continuously during that time, until a power surge took out the voltage regulator board. Bought the RS-35A noted above to replace it, it was cheaper than buying a replacement board from Astron. KB3ERQ now has that unit, to experiment with to see if he can get it going again.

I've also had an RS-12A (been running the V/UHF rig for over 25 years), a couple of RS-7's, and a host of others from time to time. Treat them decently, they'll run almost forever.

[kb2vxa]

All this talk about power supplies and everybody forgot that a battery is a flywheel, that barely able to power a CB supply is an engine. I had no problem powering even a 100W Part 90 FM transceiver re-tuned for ham use off a large car battery kept charged by a supply like that, just left it on 24/7. KISS, keep it simple stupid. Eh, now I have a 60A regulated supply somebody gave me, there is a Santa Claus after all.

[K9CCH]

All this talk about power supplies and everybody forgot that a battery is a flywheel, that barely able to power a CB supply is an engine. I had no problem powering even a 100W Part 90 FM transceiver re-tuned for ham use off a large car battery kept charged by a supply like that, just left it on 24/7. KISS, keep it simple stupid. Eh, now I have a 60A regulated supply somebody gave me, there is a Santa Claus after all.


So you're saying a car battery would power the radio, and the 1.75a power supply would recharge the battery?

[WX7P]

They BARELY pay me straight time. My little $14/hr public safety pay doesn't really give enough room for hobbies.

You should move to Marin County, CA.

I had some business dealings with Marin based dispatcher was making 100K plus (with overtime) back in the mid oughts.

Granted, it is a wee bit more expensive to live there (San Rafael, CA-reference point)

You could work at the Blue Roof Inn! AKA the Marin County Jail/Courthouse! Designed by Frank Lloyd Wright!

10180

[NQ6U]

You could work at the Blue Roof Inn! AKA the Marin County Jail/Courthouse! Designed by Frank Lloyd Wright!

10180

That place is so kewl! it's like an alien artifact that somehow ended up in the Marin County hills.

[W7XF]

So you're saying a car battery would power the radio, and the 1.75a power supply would recharge the battery?
Yes, it will. Just remember to turn off the PS before you play radio. 1.75A should keep the battery in fine shape if turned on before you go to your slave labour.
Best bet would be a deep cycle battery (marine or RV battery) which you can easily buy at Ghetto-Mart, O'Reilly's or AutoZone.

[kb2vxa]

They call me Mellow Yellow, quite rightly. But why turn off the power supply... at all? Mine ran 24/7/365 and trickle charged the battery, remember, any current in excess of what is supplied by the PSU comes from the battery. The bottom line is the supply will only put out so much, current is limited by resistance of the transformer secondary winding, battery output is limited by the resistance of the battery, considerably less. Being a trickle charger there's virtually no chance overcharging the battery, as terminal voltage rises charging current drops until it's down to a few milliamps. Eh, I used a car battery since I never deep cycled it, no need to spend so much money when the local junk yard is full of old car batteries. Lemme tell you something, the junkies down by Rahway (NJ) Prison were Ghetto Mart before Walton built his empire. Auto Zoned, what happens automatically when your stash falls in the campfire. (Cue Rocky Mountain High; John Denver.)

Yup, that's my honey hole, a treasure trove of used car parts for rock bottom prices, just bring your tool box. Before that a gold mine for tube type car radios great for BCB DXing back in the day. Now radios and the band suck, oh well.

[wa6mhz]

A Deep Cycle battery, when even slightly discharged, is going to draw more than 1.75 in recharge. High current will stress that pass transistor in the PS, which may endanger it. I SURE wouldn't have the radio even connected in an OFF state when trying that (Some circuits are still energized when the radio is off, thus they are vulnerable to Overvoltage)

I am really worried that the pass transistor on that PS is going to SHORT. Then it will be GAME OVER! Please don't have the radio anywhere NEAR that battery when U try and charge it with that PS. And monitor the battery with a voltmeter when U do.
73

[K9CCH]

I'm not doing anything with a battery. Or that power supply.

[N8YX]

That power supply is good for use as a memory backup power source for rigs or other equipment which requires external keep-alive voltage...or to run a TNC or similar low-draw shack accessories. I used one of those for years as a power source for a remote-controlled antenna polarity switch.

If you're worried about overcurrent conditions, install some form of passive (fuse) or active current limiting circuitry in series with the output of its pass transistor.

The ideal multi-multi shack power supply would consist of a 14v, 5000+ AH combination of deep-cycle and float-type batteries which are charged via at least two disparate methods (wind/solar, wind/mains, etc) through a charge controller-regulator-distribution bus arrangement. This takes a lot of space but you make up for it with greatly reduced EMI/QRN near-field levels. Of course, most of us are stuck using a mains-driven DC supply due to these constraints but if you have enough room for a bank of 4-8 100AH deep cycle batteries you can connect them to a supply through a charge controller (such as the unit offered by West Mountain Radio) and have yourself a nice little auto-failover DC setup.

[K9CCH]

That power supply is good for use as a memory backup power source for rigs or other equipment which requires external keep-alive voltage...or to run a TNC or similar low-draw shack accessories. I used one of those for years as a power source for a remote-controlled antenna polarity switch.

If you're worried about overcurrent conditions, install some form of passive (fuse) or active current limiting circuitry in series with the output of its pass transistor.

The ideal multi-multi shack power supply would consist of a 14v, 5000+ AH combination of deep-cycle and float-type batteries which are charged via at least two disparate methods (wind/solar, wind/mains, etc) through a charge controller-regulator-distribution bus arrangement. This takes a lot of space but you make up for it with greatly reduced EMI/QRN near-field levels. Of course, most of us are stuck using a mains-driven DC supply due to these constraints but if you have enough room for a bank of 4-8 100AH deep cycle batteries you can connect them to a supply through a charge controller (such as the unit offered by West Mountain Radio) and have yourself a nice little auto-failover DC setup.


I ran this through google translate, and I still dont understand a word you said.... :mrgreen:

[W7XF]

مرحبا.
يمكنني استخدام مترجم جوجل، أيضا.
أطير طائرة هليكوبتر الوردي بيل 47 مع وحدة الطاقة المساعدة.
وأنا لا تزال تريد تاكو!:-P

[K9CCH]

I got your taco....

[W7XF]

I got your taco....
Oh, you do??

[K9CCH]

Yeah. Her name is Shirley and she likes it rough.

[W7XF]

Yeah. Her name is Shirley and she likes it rough.

:vomit: :vomit: :vomit:

[K9CCH]

ROTFLMAO!!!!

[W2NAP]

They BARELY pay me straight time. My little $14/hr public safety pay doesn't really give enough room for hobbies.

shit, you should move here. $14 a hour here and you could live like bill gates.... ok maybe not like bill gates but you would have it made. AND with the crime around here you would always have busy shifts with all the shootins,stabbings,drugs,ect,ect

[kb2vxa]

"Yeah. Her name is Shirley and she likes it rough."

Sounds like one of Rudi's friends.

"They BARELY pay me straight time."

There's a gay joke in there somewhere.

[WØTKX]

The ideal multi-multi shack power supply would consist of a 14v, 5000+ AH combination of deep-cycle and float-type batteries which are charged via at least two disparate methods (wind/solar, wind/mains, etc) through a charge controller-regulator-distribution bus arrangement. This takes a lot of space but you make up for it with greatly reduced EMI/QRN near-field levels. Of course, most of us are stuck using a mains-driven DC supply due to these constraints but if you have enough room for a bank of 4-8 100AH deep cycle batteries you can connect them to a supply through a charge controller (such as the unit offered by West Mountain Radio) and have yourself a nice little auto-failover DC setup.

I have 18 90AH deep cycle gel batteries stored, use 'em for camping and loan them out to locals for FD and such. Charge 'em up every 4 months, they only take 3-4 minutes to top off at 1 amp or less. Surplus pulls from work. I have more available soon. Really need a budget for solar/wind power. I get the batteries for free.

The West Mountain unit is sitting here, new in the box. Not enough time for projects. Sigh.

It really does help the noise level. Was not noticeable living in the city, but living here, the noise floor drops.

[K9CCH]

"They BARELY pay me straight time."

There's a gay joke in there somewhere.



ROTFLMAO!!? Never even saw it....

[kb2vxa]

We see... what you do not.

[K0RGR]

I use one of those RadioShack wonders to charge 12 volt items in the garage - but not car batteries. I used it to charge my FT-817 for a while. I typically use it recharge the small 'jump' batteries I use in the winter.

I have two of the Astron Rx-35's one M model, one S model. I have had the M model with the meters in use continuously for about 40 years. I bought the S model for $100 on EBay, and it's been turned on for me for several years. I don't know how old it is, but it is an older model. I've never had to fix one (knock wood) but I'm confident that the copious quantities of online documentation on troubleshooting them and availability of most parts, I would not have a problem doing so.

Now, having said that, I don't think the MFJ supply proposed looks bad at all. Unless you're doing real weak signal work, you'll probably not notice that it's a switching supply, and switching supplies usually fail in a 'safe' mode that won't harm your gear. The analog supplies can easily die in a fashion that puts out too much voltage if the over-voltage circuit isn't done correctly.

Still, owning an analog Astron is like owning a 'piece of the rock'. And it will weigh like it, too.