Usually when those transisters fail, they short and the o v p kicks in. 
He needs to check voltage at the supply terminals and at the radio to 
see what is really going on.  I often replace those pass transisters 
with darlingtons for two reasons.  They don't take near as much drive 
current, less of a train on the driver transister.  This driver is often 
mounted on the board or on the bottom of the supply.  Other advantage of 
using darlingtons, such as ecg 247 or ecg 249, if I remember right, is 
they almost never short when they go bad.
73
Butch
WA0VJR
Node 3148
Wallace, ks.


On Mon, 23 Nov 2015, Tom Behler 
wrote:

> Steve:
>
> I know exactly where those transistors are on the RS35.
>
> I guess my growing suspicion is that something isn't as it should be in the
> supply, and I'd rather be proactive, than reactive.
>
> Will let you know what I find out when I do the re-arranging this week-end,
> maybe as early as Friday before the CQ WW DX contest!
>
> Tom Behler: KB8TYJ
>
>
> -----Original Message-----
> From: For blind ham radio operators [mailto:[log in to unmask]]
> On Behalf Of Steve Forst
> Sent: Monday, November 23, 2015 7:55 PM
> To: [log in to unmask]
> Subject: Re: Kenwood PS53 Power Supply Manual
>
> Tom,
>
> Sounds good.  As others have said, the supply is rated and was sold as a
> match for a 100 watt transceiver.  It will work fine for you.
>
> Will be curious   to see  if it solves the problem.    I understand the
> transistors on the Astron's can sometimes fail.  The 35A has 4 of them.
>   You can feel them on the rear heat sink,  in the wide gaps between
> the fins.  2 transistors in each gap.   Not sure if one or more of the
> transistors failing would give  the symptoms you see, but perhaps.
>
> 73, Steve  KW3A
>
> On 11/23/2015 7:36 PM, Tom Behler wrote:
>> Steve:
>>
>> Based on the specs for the PS53, and based on what you and others have
>> shared, I am going to try the following approach, at least for now.
>>
>> I'm going to take the RS35 off line, and use the PS53 to run my TS590,
>> the TW1, and MFJ998 auto-tuner.
>>
>> I have a switching power supply that will be quite adequate for the
>> TMV71A, so will connect that rig to that supply separately.
>>
>> I probably won't get to this until the week-end, but I'll be sure to
>> let everyone know what, if any difference I see in output power with
>> this new configuration.
>>
>> Thanks to all for your patience as I continue to sort this through.
>>
>> Tom Behler: KB8TYJ
>>
>>
>>
>>
>> -----Original Message-----
>> From: For blind ham radio operators
>> [mailto:[log in to unmask]]
>> On Behalf Of Steve Forst
>> Sent: Sunday, November 22, 2015 10:10 PM
>> To: [log in to unmask]
>> Subject: Re: Kenwood PS53 Power Supply Manual
>>
>> Tom,
>>
>> The TW-1 current draw is minimal.  The 998 auto tuner  needs 1.5 amps
>> for tuning, but  while the tuning process is going on the radio is
>> only putting out 10 or 15 watts, so current draw by the radio at this time
> is
>>    low.
>>
>>
>> If running the amp, you are probably only driving with 50-60 watts,
>> depending on band, so  plenty of headroom for the ps.
>>
>> If you are going to obsess about the power supply, maybe limit your
>> barefoot operations to 80 watts.  The other station will never know
>> the difference, and you will sleep better.
>>
>> I think this supply will suit your needs, but don't think I would  add
>> more stuff to be powered at the same time.
>>
>> 73, Steve KW3A
>>
>> On 11/22/2015 9:48 PM, Tom Behler wrote:
>>> Steve:
>>>
>>> Thanks for the Universal Radio link.
>>>
>>> I'll definitely check it out.
>>>
>>> I run the TS590, my MFJ 998 auto-tuner, and my TW1 off the RS35 via a
>>> rig runner.  My thought is to run those devices with the PS53, if I
>>> can get away with it.  Of course, my ALS600 has its own separate
>>> power
>> supply.
>>>
>>> I also have the TMV71A connected to the RS35 via the rigrunner as
>>> well, but I do have a little switching power supply I could power
>>> that
>> with if needed.
>>>
>>> May ultimately have to bite the bullet and buy a new power supply,
>>> but don't want to do that unless it is absolutely necessary.
>>>
>>> At the same time, I don't want to risk damaging any equipment, and
>>> creating bigger problems.
>>>
>>> Tom Behler: KB8TYJ
>>>
>>>
>>> -----Original Message-----
>>> From: For blind ham radio operators
>>> [mailto:[log in to unmask]]
>>> On Behalf Of Steve Forst
>>> Sent: Sunday, November 22, 2015 9:34 PM
>>> To: [log in to unmask]
>>> Subject: Re: Kenwood PS53 Power Supply Manual
>>>
>>> Tom,
>>>
>>> Here is a link to  the Universal Radio page on the discontinued power
>>> supply, with some basic specs:
>>>
>>> http://www.universal-radio.com/catalog/hamps/2816.html
>>>
>>>
>>> I'm not sure what the 16 amp  raiding you are finding on the unit
>>> represents.  As a comparison" My old Astron RS-20 was rated at 16
>>> amps continuous (I think until the cows come home) and  rated at 20
>>> amps for a shorter duty cycle.  You shouldn't have any problem with
>>> your
>> supply.
>>>       Maybe running 100 watt RTTY would put a strain on it, but  CW
>>> is less of a duty cycle, and SSB even less.
>>>
>>> I think you run other stuff off  your main station supply, so  a 35
>>> amp unit is probably better, but for what you are trying to do  now in
>>> testing, just   hook it up  and see how it goes.
>>>
>>>
>>> I would try and reconnect with as much of the existing wiring as
>>> possible to the new supply, so you are comparing apples to apples.
>>>
>>> 73, Steve KW3A
>>>
>>>
>>>
>>> On 11/22/2015 9:10 PM, Tom Behler wrote:
>>>> Hello, everyone.
>>>>
>>>>
>>>>
>>>> I tried to do a google search for the manual for the Kenwood PS53
>>>> power supply, in order to get the specs on the unit, but ran into an
>>>> interesting problem.  The manual is a scanned image file on the two
>>>> web sites I found, and when I tried running it through the Jaws
>>>> Convenient OCR process, the conversion process stopped in mid-stream.
>>>> Then, I tried sending the file
>>> to
>>>> roboBraille, and got a message saying the conversion process could
>>>> not
>>> occur
>>>> because the document was "read protected".
>>>>
>>>>
>>>>
>>>> Once again, if someone has a text version of the manual, please send
>>>> it my way.
>>>>
>>>>
>>>>
>>>> [log in to unmask]
>>>>
>>>>
>>>>
>>>> In the meantime, I'll keep seeing what I can do here.
>>>>
>>>>
>>>>
>>>> Tom Behler: KB8TYJ
>>>>
>>>>
>>>>
>>>
>>
>
>