QTH.COM Swap Chat

I made a deal with Ken (KG4LQD). He sent me an Astron VS-50M power supply that he said looks good and works great. When I received the power supply I hooked it up to my radio and found out that it only will put out 10 amps max, nothing more. It is rated at 50 amps surge, 40 amps continuous. The box he shipped it in looks good no damage and the power supply looks fine so it does not look like it was damaged in shipment to me. Looking inside of it nothing looks damaged.
I e-mailed him and told him the problem. He answered back saying he does not know why this should be, it worked fine for him. I then checked some other radio's with it and the same result, will not go over 10 amps .
I since have sent him several other e-mails asking some questions and now get no answer from him.
I just want to let people know that if Ken offers you a trade, beware.
............Wally, N9VAO

n9vao wrote:I made a deal with Ken (KG4LQD). He sent me an Astron VS-50M power supply that he said looks good and works great. When I received the power supply I hooked it up to my radio and found out that it only will put out 10 amps max, nothing more. It is rated at 50 amps surge, 40 amps continuous. The box he shipped it in looks good no damage and the power supply looks fine so it does not look like it was damaged in shipment to me. Looking inside of it nothing looks damaged.
I e-mailed him and told him the problem. He answered back saying he does not know why this should be, it worked fine for him. I then checked some other radio's with it and the same result, will not go over 10 amps .
I since have sent him several other e-mails asking some questions and now get no answer from him.
I just want to let people know that if Ken offers you a trade, beware.
............Wally, N9VAO

wally how many watts out is your radio rated at 100 watts 50 watts 25 watts
and how many amps is it supposed to draw ???

chuck

I guess I should have added this to my original posting on Ken (KG4LQD).
I beleive in giving a man the benefit of a doubt. Had he answered more than just my one e-mail and not respond to the others I mite have thought otherwise.
To ignore my request to answer some other questions makes me beleive he knew it was a defective power supply.
..........Wally, N9VAO

Wally,
Not knowing for sure, but I will guess that something got bumped in shipment. Call Astron at:
949-458-7277 • FAX:949-458-0826

E-MAIL: sales@astroncorp.com

Please have the covers off when you call and I believe they will help you repair your P/S problem on the phone..

73, Terry

To Terry N8ERM,
Thank you for the info. I will contact them tomorrow.
.........Wally, N9VAO

Wally I can understand you concern for him not answering your e-mails but as Chuck asked what kind of radios were you testing it with? If it was the typical 2 meter or dual band mobiles they will only draw about 10 amps on high and a power supply will only put out what is required to power the radio. So if the radio only pulls 10 amps the power supply will only put out 10 amps. I only raised this question because not many radios (if any) are cable of maxing out this power supply.

KB9VXQ,
I guess I should have put the reply about what radio's I connected the supply to here but I sent an e-mail direct to the sender.
I hooked the supply first up to my Icom IC-V8000. 75 watt 2meter radio that draws 15 amps. Keyed the radio and only showed 23 watts out and supply showed 10 amps. I then connected my Icom IC-746 HF rig, keyed the radio and showed around 20 watts out and supply showed 10 amps again. connecting both radio's back to the old supply I have and they both had full out put.
..........Wally, N9VAO

Thanks for the reply Wally. That clears up things. Deffinetly sounds like it has a problem. Him not answering e-mails isn't good either.

It sounds to me like a problem with the overcurrent foldback or current sensing circuit. A purely speculative possibility is vibration in the shipping caused one of the current sense resistors to break free of it's solder connection (probably several sense resistors in parallel). These would likely be large physical size resistors, and with mass and vibration you can fracture a solder connection. Now, admittedly I've never seen the inside of the Astron unit, but if I was a betting man that's the way I'd bet sight unseen. A call to Astron, as suggested before, may help you solve it. Let us know how it turns out.
Marc N9KHI

Something does not add up here. A few tests will point to the answer.

With the Icom in line and in the TX mode , full power out. What is:

1) The voltage measurement right at the radio connector ?
2) The current reading on the Astron?
3) The voltage measurement on the Astron measured at the terminals on the rear?

Astron power supplies use a 14 pin DIP (LM-723CN) for regulation sensing. If the current is railed at 10 amps , and the rig is only putting out "low" power , then the voltage drop has to be huge at the radio connector OR the Astron will shut down.

I have seen this happen when fuse holders in factory Kenwood power cables go bad. A resistive material builds up on the fuse caps and will show the proper VDC until current is drawn , then it drops

This might be a dumb remark, but, do you have the current limiter control turned to max?? I believe the VS-50 has front panel controls for voltage AND current.

Mike

WOW , good call on the current adjustment , The VS-50M does have that option. I think he is going to find that is was counter clockwise.

I mite not know a lot about this power supply but I know enough to turn the knob on the front of it that says amp adjust.
With that adjustment turned all the way to max (clockwise) I only get 10 amps. Turning it back takes it down to zero amps.
Measuring and setting voltage (13.8) I used a digital volt meter connected at the power supply terminals. When I keyed the radio's the voltaged went down to 12.7
I thank all of you for helping me.
..........Wally, N9VAO

I'm still thinking it's a current sense resistor issue. The voltage drop measured across a low value fixed resistor provides the current control feedback that the regulator uses to adjust the drive to the pass device that ultimately adjusts both current and voltage. If you are proficient with a soldering iron and know your way around a pc board, open it up (unplugged!) and give the board a good visual inspection on both the component side and the solder side. What you are looking for are questionable solder connections or burned resistors.
Unfortunately it's the wrong time of year or I'd be vacationing near your QTH (fishing on Grindstone lake) and I'd drop over and take a peek at it for you.
73,
Marc N9KHI

Thanks Marc for the info, I'll check all that out.
.........Wally, N9VAO

Well everyone this will be my last reply on this power supply and here's why.
I opened up the supply again and took a detailed look at everything. The board is mounted upside down so I removed it and saw that one resistor had a wire soldered to it (and a poor job at that) and something was cut off from the board. The two stubs from it are still there so not having a schematic I'm not sure what it was. Also looking around the inside I see where other things were replaced because I'm sure Astron does not do this poor of a solder job.
If Ken (KG4LQD) or some other person did this it came to me this way and was not damaged in shipping. I beleive Ken knew it did not work properly and sent it to me.
Again all I can say is if you deal with KG4LQD, beware!
.............Wally, N9VAO

Wally...here is a url that has the schematics for the vs35 and 70...the 50 can't
be much different. Perhaps this will help. 73...Sam W8VVE

http://www.repeater-builder.com/astron/ ... index.html

I guess the bottom line is N9VAO thought he was purchasing a working power supply and he should not have to repair it. It does appear that something is wrong with it and it's unlikely that N9VAO damaged it by connecting it to his Icom IC-V8000. If seems that the fair solution would be for him to return it and for KG4LQD to refund his money.

I do have one more post I want to make about this power supply. I have received several e-mails direct to me on ideas and suggestions on what to check on the supply.
I thank all of you, for posting here or by e-mailing me for your help and hope you all have good dealings in the future.
.............Wally, N9VAO

Note to all:
KG4LQD (Ken) has changed his call. As of September 26th he is now K4NOL.