[AMRadio] Low Power AM?


Brett Gazdzinski Brett.Gazdzinski at verizon.net
Sun Nov 23 23:50:30 EST 2008


Unless you are talking about some particular rig, this is not so.
I run tubes well under their maximum plate dissipation ratings all the time, 
and they last longer that way.

With some setups, you have to watch the screen current, but otherwise, there 
is no problem at all.

Triodes surely don't care about under loading below maximum plate current.

I think the term off resonance is wrong for light loading, its resonant, but 
delivering less power to the load.

Brett
N2DTS

----- Original Message ----- 
From: "AirRadio" <AirRadio at dsl.pipex.com>
To: "Discussion of AM Radio in the Amateur Service" 
<amradio at mailman.qth.net>
Sent: Sunday, November 23, 2008 3:55 PM
Subject: Re: [AMRadio] Low Power AM?


>I would think most AM transmitters would not mind running RTTY, after all 
>most of the ww2 military tx's ran RTTY most of the time anyway, esp in the 
>RAF here, like the Marconi T1509, 350w mainly RTTY.  2x 813 modulating 2x 
>813 in the PA.
> Running the 6146 off resonance or underloaded will damage them faster than 
> if the plates were run a bit hot, the best way is try it and see, watch 
> the plate colour and if they are too red then back off the input a little 
> not the other way round.
> 73 Max M0GHQ
>
> ----- Original Message ----- 
> From: "rbethman" <rbethman at comcast.net>
> To: "Discussion of AM Radio in the Amateur Service" 
> <amradio at mailman.qth.net>
> Sent: Sunday, November 23, 2008 8:48 PM
> Subject: Re: [AMRadio] Low Power AM?
>
>
>> Bob,
>>
>> While the plate transformer may well handle that, you are tuning off 
>> resonance of the PI network.  That results in tuning off the Plate dip. 
>> I would NOT imagine that this concept would do the 6146s any good at all.
>>
>> I would suspect that a reduction of Drive would be wiser.
>>
>> Bob - NoDGN
>>
>> Bob Macklin wrote:
>>> Can't you just run at reduced input by reducing the loading? Then run 
>>> the
>>> tube(s) at the CCS rating. The power transformer should take that.
>>>
>>> Bob
>>> K5MYJ
>>> ----- Original Message ----- 
>>> From: "rbethman" <rbethman at comcast.net>
>>> To: "Discussion of AM Radio in the Amateur Service"
>>> <amradio at mailman.qth.net>
>>> Sent: Sunday, November 23, 2008 12:14 PM
>>> Subject: Re: [AMRadio] Low Power AM?
>>>
>>>
>>>
>>>> George,
>>>>
>>>> Good question!  There is NO mention of RTTY operation ANYWHERE in the
>>>> Apache Manual.
>>>>
>>>> I'm also not sure how you can safely reduce the power out put following
>>>> the tuning procedures, WITHOUT doing some damage to some components.
>>>>
>>>> It does just fine on AM and CW.  Mixed results on SSB with the SB-10.
>>>>
>>>> Bob - N0DGN
>>>>
>>
>> -- 
>> Bob - NØDGN
>>
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>
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