Well, if the SWR is too low for those tubes, just decrease the grid drive a 
little, bring the output down just 5 watts or so and you'll get a couple 
more years use out of those tubes. 6146 tubes are quite rugged, I've had 
uncanny usage out of 6146s keeping on and on.
Isn't that what the 520SE has? Horizontal output tubes, might be a little 
more fragile, so ... Isn't that what some of the Swan radios had?

Curtis Delzer
W B 6 H E F
Fessenden, North Dakota; 58438-7300
----- Original Message ----- 
From: "Shaun Oliver" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, March 17, 2008 9:49 AM
Subject: Re: tone osilator.


one other thing I've heard is that if your tubes see too low a vswr,
they apparently are too efficient and will ware out quicker as a result.
pardon the language but, load of shit if you ask me.
sure you are able to run an old tube radio on an antenna that's not
exactly matched but you can do it with any radio although the valve rigs
seemed to me, to have a higher tolerance for it. not that I'm going out
of my way to run a vswr of 10:1


On 18/03/2008 1:41 AM, the old scribe known as Shaun Oliver was able to
impart this pearl of wisdom:
> tuning ain't the problem. I'm familiar with the process, and not only
> that it's like riding a bike, you never forget. I suppose it a slight
> case of information overload, one fellow tells you one thing the manual
> says something else another fellow says a third thing by which time
> you're pulling your hair out, and going nuts with information overload,
> so much so you can't tell the diffence between the end you talk out of
> and the end you pass gas out of.
> I just want to be absolutely sure as I'm well aware of the cost of
> tubes. although I do have the good fortune of being supplied with a
> spare set should I buy the yaesu ft201. it's still got it's original
> 6js6c finals and 12BY7 driver. and the fellow has all three.
> while I'm on it, is it easy for a blind person to nutralise the finals
> once they've been replaced or are we at somewhat of a disadvantage with
> regards to this? I'd like to be as independent as possible as the leader
> of the opposition is not at all interested in ham radio.
>
>
> On 18/03/2008 1:33 AM, the old scribe known as Howard Kaufman was able
> to impart this pearl of wisdom:
>> Sean what you have to realize, is that retuning a radio is a simple
>> operation.  Let alone does it give you the best possible signal, but it
>> protects your equipment and valves.  Those valves are not going to get 
>> any
>> easier to find over the years, hence forth, their price will continue to
>> rise.  If you are kind to your radio, it is possible to get twenty years 
>> out
>> of a set of finals.  That means tune your finals, and make sure the radio
>> sees a flat SWR.  The audio oscellator is more accureate than the meter.
>> Backk off the drive until you get comfortable with the process.  10 watts
>> will be plenty for adjustment power.  I ran a set of 6JB6 sweep tubes for 
>> 25
>> years on that system.  Those are no near as rugged as the 6146 tubes that
>> the kenwoods used.
>>
>>
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>>
>
>
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