[Swan] SW 240 lineage questions

[Rick Gouge]

Thankyou for the info. I will pull it down soon and have a look. Do you know 
where i could get a shop manual for the SW240? Plus my SW240 has the square 
bezel on both the meter and freq readout. Rick VE7RiK
----- Original Message ----- 
From: "Greg Mijal" <bluebirdtele at embarqmail.com>
To: "Discussion of equipment manufactured by Swan" <swan at mailman.qth.net>; 
<W9RAN at oneradio.net>
Sent: Monday, November 03, 2008 9:24 PM
Subject: Re: [Swan] SW 240 lineage questions


> Flair up?
> What happened?
> Frequently the plate RF choke will toast.  You may have also heated up a
> resistor under the tube socket
> If you have a scope you should see around 20 - 30 v Peak to peak in the
> transmit mode.
> Suggest you pull out the Plate RF choke and inspect it for burns.  If you
> have an inductance meter you should have at least 90 uh or so for a good
> choke.
> The 240 is worth saving even if it doesn't have an S meter on it.
> By the way I've seen both kinds of 240's one has a very square bezel 
> around
> the freq read out, the other is slightly different.
> Love those Swans.
> 73's
> Greg
> WA7LYO
> Kinston NC
> ----- Original Message -----
> From: "Rick Gouge" <rickgouge at shaw.ca>
> To: <W9RAN at oneradio.net>; "Discussion of equipment manufactured by Swan"
> <swan at mailman.qth.net>
> Sent: Monday, November 03, 2008 9:52 PM
> Subject: Re: [Swan] SW 240 lineage questions
>
>
>> Robert,I also have a SW240 in beautiful condition. I was trying it on AM
>> along time ago and i guess i had the drive to high and had a RF flareup 
>> in
>> the finally cage. Since then i can not get full drive out of it on SSB. I
>> have alot of new 6DQ5. I put a new one in and no change. I also tested 
>> all
>> other tubes as well. All are good. So i think it must have something to 
>> do
>> with another component in the RF cage. I have a operators manual but no
> shop
>> manual. I hope this makes some sense to you. I would be greatful for any
>> help on this matter. Rick VE7RiK
>> ----- Original Message -----
>> From: "Robert Nickels" <ranickel at comcast.net>
>> To: "Discussion of equipment manufactured by Swan" <swan at mailman.qth.net>
>> Sent: Monday, November 03, 2008 5:09 PM
>> Subject: Re: [Swan] SW 240 lineage questions
>>
>>
>> > Bill Clarke wrote:
>> >>
>> >> On the PA (6DQ5) pin 3 has a 5 watt 5 ohm ceramic resistor to ground.
>> >> It does not look original and is not on the diagram I have. What
>> >> might the reason for this modification have been?
>> > Bill, that's a hack to re-balance that leg of the series-parallel 
>> > heater
>> > string for use with the "dark heater" version of the 6DQ5.  RCA
> introduced
>> > this version of the tube in the 60s as a "running change" i.e. no 
>> > change
>> > in marking or designation.  However the dark heater version draws
>> > substantially less current than the original 6DQ5 and thus the Swan 240
>> > filaments will be really unbalanced if one is just plugged in.   I did
> the
>> > same thing to prove to myself that this was  the case before learning
>> > about the dark heater issue and have been trying to spread the word 
>> > ever
>> > since.    In most applications with 6.3 volt filament wiring, the new
>> > version was a plus as it required less filament current, but not for 
>> > the
>> > Swan 240!
>> >
>> > By the way, I'd recommend restoring it.  Several of us use them
> routinely
>> > on the Vintage Sideband Net and I like the broader sounding audio.  It
>> > also puts out a heck of a signal for having only one inexpensive final
>> > tube!  I also have a spare TCU remote VFO console available if anyone's
>> > interested.
>> >
>> > 73, Bob W9RAN
>> > _______________________________________________
>> > Swan mailing list
>> > Swan at mailman.qth.net
>> > http://mailman.qth.net/mailman/listinfo/swan
>>
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