I have one of those MFJ 4125 MightyLite supplies. ... It is a nice little
unit, but, as you say, the fan runs constantly and gets rather annoying at
times.
Right now, it is in my office at work, where I have an old TMV7A, and is
only used very infrequently.
It would be a great switching supply for a go kit.
Tom Behler: KB8TYJ
-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Butch Bussen
Sent: Thursday, November 26, 2015 8:27 AM
To: [log in to unmask]
Subject: Re: Power Supply Update
I'm not a big fan of switching supplies, although they're nice for portable
operation. I have an m f j which is a good supply, but it has a fan which
runs all the time the supply is on. The fan should have been temperature
controlled. have anough fans running here without adding another one.
73
Butch
WA0VJR
Node 3148
Wallace, ks.
On Wed, 25 Nov 2015, Dr. Ronald E. Milliman wrote:
> Tom, I have an Astron RS35 supply just like yours, and it went out on
> me, much like yours did. I took it over to a friend of mine who is
> quite an excellent electronics technician, and he found the problem
> immediately and repaired it. In my case, it was a regulator
> transistor. It was a very common, readily available part, and so, he
> had no problem fixing it. Those supplies are fairly easy to work on.
> However, they are not worth investing very much money repairing them.
> You can purchase a new MFJ or JetStream for relatively little money.
>
> Ron, K8HSY
>
>
>
> -----Original Message-----
> From: For blind ham radio operators
> [mailto:[log in to unmask]]
> On Behalf Of Pat Byrne
> Sent: Wednesday, November 25, 2015 9:56 PM
> To: [log in to unmask]
> Subject: Re: Power Supply Update
>
> Tom,
> Do all of the pass transistors feel the same amount of warm? Perhaps
> one has failed. Is there anyone of your acquaintance who would be
> competent to help you troubleshoot? I know that can be a challenge.
> is it feasible to replace all components except the transformer? And
> I remember recently reading on this list that overall voltage
> regulation is better with a switching supply than a linear. No answers,
just a few thoughts.
> Eat too much for dinner tomorrow before deciding this weighty issue!
> Pat, K9JAUAt 08:47 PM 11/25/2015, you wrote:
>> Hello, everyone.
>>
>>
>>
>> For those who might be interested, I have an update to share
>> regarding my Astron power supply woes here at the home QTH.
>>
>>
>>
>> It turns out that I think I was correct in suspecting that something
>> is failing in my Astron RS35 supply.
>>
>>
>>
>> I connected my TS590 to my older Kenwood PS53 supply, and my output
>> power is now a solid 100 watts according to the TS590's internal
>> swr/watt
> meter.
>> This is on the same 40-meter resonant frequency where I tested the
>> RS35 the other day, and got 75 watts out according to the TS590
>> meter. My
>> TW1 reading with the PS53 supply was 90 watts out, compared to 58
>> watts out with the RS35.
>>
>>
>>
>> I then connected my TMV71A to the PS53 power supply, and with a 1.2
>> to
>> 1 SWR reading, got an output power reading of 44 watts on 2 meters,
>> and
>> 36 watts on 440, according to my TW2.
>>
>>
>>
>> In my view, this indicates that my problem with reduced output power
>> likely has been related to the RS35.
>>
>>
>>
>> So, at least in the short term, I'm going to need to re-configure
>> things in my shack here.
>>
>>
>>
>> I'm going to run the TS590 setup using the PS53, and my TMV71A, using
>> a Tentec 963 30-amp switching supply that I picked up at a local swap
>> last summer.
>>
>>
>>
>> My next decision will be what to do with the RS35. I'm going to see
>> if I can get one of the guys in our local club to help me
>> troubleshoot the situation, but I'm not sure how successful that will be.
>>
>>
>>
>> I'm actually seriously thinking about purchasing a completely new
>> power supply, since I prefer to use a rig runner for connecting
>> everything in my shack to a single power supply.
>>
>>
>>
>> And this brings me to a question:
>>
>>
>>
>> Does anyone have recommendations for a good replacement supply? I am
>> ok with a linear supply, since it just sits on a shelf of my
>> operating desk here at the home QTH. To be safe, I would like
>> something with at least the capacity of the RS35,, or maybe even
>> somewhat greater if it is reasonably affordable.
>>
>>
>>
>> I'd consider another RS35, but with some of the quality control
>> reports I have received recently, I'm now not so sure that's the best
>> route for me to go.
>>
>>
>>
>> Any thoughts/recommendations?
>>
>>
>>
>> Tom Behler: KB8TYJ
>>
>>
>>
>>
>>
>>
>
>
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