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
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>
>
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