Lou:
I just tried what you suggested, with very good results.
I took the TS480 with the power supply in question, and brought the power
down to 10 watts. Then, I tuned in the same frequency on my Icom IC746,
with no antenna, so I could hear myself. I did the test in A M mode first,
and heard absolutely no hum at all. Then, I switched both rigs over to CW,
and the CW I heard was totally clear as a bell--clean as a whistle,
using both an external speaker and headphones.
So, I think I'm ok with the power supply.
Thanks for a great suggestion.
73 from Tom Behler: KB8TYJ
----- Original Message -----
From: "Lou Kline" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, December 27, 2007 6:45 PM
Subject: Re: using TS480 with 35-amp Samlex switching power supply
> Hi Tom.
>
> If you can listen to yourself on a receiver without an antenna (so you
> don't overload the frontend), put the receiver in AM mode and tune in your
> carrier. See if you can hear either 60 Hz or 120 Hz modulation on the
> carrier. If you can't, I probably wouldn't worry much about it. If you
> can, then you might want to look for a different supply.
>
> 73, de Lou K2LKK
>
>
>
> At 10:56 PM 12/26/2007 -0500, you wrote:
>> John:
>>
>>The fan in the radio does come on every so often, after I've transmitted
>>for
>>a while, but the hum I'm hearing is definitely coming from the power
>>supply.
>>It occurs whenever I transmit in CW on 100 watts. It actually corresponds
>>with the dits and dahs that I send. If I then go to RTTY mode, and use
>>the
>>PTT on the stock mic, the hum is continuous. It starts when I key the
>>transmitter, and ends whenever I unkey.
>>
>>And, it sounds very much like the kind of 60-cycle hum that you can hear
>>if
>>you listen very closely to a transformer-type power supply like my RS35.
>>
>>Again, in the Samlex, it happens when I key up, and ends when I unkey.
>>
>>73 from Tom Behler: KB8TYJ
>>
>>----- Original Message -----
>>From: "John Miller" <[log in to unmask]>
>>To: <[log in to unmask]>
>>Sent: Wednesday, December 26, 2007 9:46 PM
>>Subject: Re: using TS480 with 35-amp Samlex switching power supply
>>
>>
>> > I've never run CW on my 706, but I've run everything else at about full
>> > power and even a second radio some times, VHF, for some events, pulling
>> > a
>> > pretty good 21 to 23 amps from that power supply and never heard a
>> > thing.
>> > That's not to say my fan doesn't work though, that's possible. I also
>> > wonder
>> > if that could be the fan in the radio you're hearing? It could be that
>> > your
>> > fan does come on then, mine has never once come on so I have no clue
>> > when
>> > it
>> > comes on or what it sounds like. I can't get that power supply warm for
>> > anything.
>> > ----- Original Message -----
>> > From: "T Behler" <[log in to unmask]>
>> > To: <[log in to unmask]>
>> > Sent: Wednesday, December 26, 2007 9:41 PM
>> > Subject: Re: using TS480 with 35-amp Samlex switching power supply
>> >
>> >
>> >> John:
>> >>
>> >> Do you get any of the hum I'm speaking of when in CW mode on 100
>> >> watts?
>> >>
>> >> 73 de KB8TYJ
>> >>
>> >> ----- Original Message -----
>> >> From: "John Miller" <[log in to unmask]>
>> >> To: <[log in to unmask]>
>> >> Sent: Wednesday, December 26, 2007 9:08 PM
>> >> Subject: Re: using TS480 with 35-amp Samlex switching power supply
>> >>
>> >>
>> >>> My samlex power supply fan takes a lot to come on, that or it doesn't
>> >>> work.
>> >>> ----- Original Message -----
>> >>> From: "Colin McDonald" <[log in to unmask]>
>> >>> To: <[log in to unmask]>
>> >>> Sent: Wednesday, December 26, 2007 9:02 PM
>> >>> Subject: Re: using TS480 with 35-amp Samlex switching power supply
>> >>>
>> >>>
>> >>>> probably the fan.
>> >>>> that's about all that can make any noise inside a switching power
>> >>>> supply.
>> >>>> The bigger supplies will have a fan that comes on automatically when
>> >>>> allot
>> >>>> of current is being drawn.
>> >>>> 73
>> >>>> Colin, V A6BKX
>> >>>> ----- Original Message -----
>> >>>> From: "T Behler" <[log in to unmask]>
>> >>>> To: <[log in to unmask]>
>> >>>> Sent: Wednesday, December 26, 2007 6:48 PM
>> >>>> Subject: using TS480 with 35-amp Samlex switching power supply
>> >>>>
>> >>>>
>> >>>>> Hi, all.
>> >>>>>
>> >>>>> I have noticed something when using my TS480 with my 35-amp Samlex
>> >>>> switching
>> >>>>> power supply.
>> >>>>>
>> >>>>> When I transmit with 100 watts, in CW mode or in RTTY mode using
>> >>>>> the
>> >>>>> stock
>> >>>>> mic, I notice a slight but audible hum coming from the switching
>> >>>>> power
>> >>>>> supply. The hum stops when I stop transmitting. I had my XYL take
>> >>>>> a
>> >>>>> look
>> >>>>> at the meters on the front of the supply, and they say I'm running
>> >>>>> at
>> >>>>> 13.8
>> >>>>> volts, and drawing about 19 amps, which is about what I'd expect.
>> >>>>>
>> >>>>> And, just for the record, I'm doing this with a resonant antenna,
>> >>>>> and
>> >>>>> just
>> >>>>> using the auto-tuner to be sure I have a perfect match.
>> >>>>>
>> >>>>> Is this slight but noticeable hum when transmitting normal?
>> >>>>>
>> >>>>> Thanks, and 73 from Tom Behler: KB8TYJ
>> >>>>>
>> >>>>>
>> >>>>>
>> >>>>> --
>> >>>>> No virus found in this incoming message.
>> >>>>> Checked by AVG Free Edition.
>> >>>>> Version: 7.5.516 / Virus Database: 269.17.9/1197 - Release Date:
>> >>>> 12/25/2007 8:04 PM
>> >>>>>
>> >>>>>
>> >>>>
>> >>>
>> >>>
>> >>
>> >
>> >
>>
>>
>>
>>
>>--
>>No virus found in this incoming message.
>>Checked by AVG Free Edition.
>>Version: 7.5.516 / Virus Database: 269.17.11/1200 - Release Date:
>>12/27/2007 1:34 PM
>
> Louis Kim Kline
> A.R.S. K2LKK
> Home e-mail: [log in to unmask]
> Work e-mail: [log in to unmask]
> Work Telephone: (585) 697-5740
>
>
|
