[NLRS] RF Concepts Amp Question

[KB0NLY]

Thanks for the info, I will have to tinker on it a bit.  I'm not so worried 
about how much power it makes as I am that its tuned correctly, if it was 
putting out close to rated power I would be comfortable using it knowing all 
was well.  Guess I'm just picky that way!

I tried it on two wattmeter's, a Bird 43 with a 500w slug, and my HM-2102 
which I then double checked against the Bird and found it was only off 3-4w. 
Not bad for an old Heathkit!

73,

Scott






----- Original Message ----- 
From: <jcplatt1 at mmm.com>
To: <nlrs at mailman.qth.net>
Sent: Friday, November 30, 2007 3:49 PM
Subject: Re: [NLRS] RF Concepts Amp Question


>
>
> Hi Scott.
>
> I do not have intimate knowledge of that particular amp, but all these
> bricks are usually the same.   The two compression caps are most likely 
> the
> tuning for the input and output stages.   I would recommend that you 
> simply
> adjust both for maximum RF output.  On these bricks there usually is not 
> an
> input  drive adjustment.  The previous user may have "detuned" these 
> tuning
> caps in order to drop the power.
>
> Unless you have a good power meter (Bird, etc), the accuracy of most power
> meters is perhaps +/- 10 % AT full scale.    At something less than full
> scale the accuracy is most likely worse than +/- 10%.
>
> And although we all like to see the power meter go way up scale, going 
> from
> 110 to 150 watts is only a 1.4 dB improvement - something that would be
> very hard for anyone to detect.
>
> 73, Jon
> W0ZQ
>
>
>
>
>             "KB0NLY"
>             <kb0nly at mchsi.com
>             >                                                          To
>             Sent by:                  "NLRS" <nlrs at mailman.qth.net>
>             nlrs-bounces at mail                                          cc
>             man.qth.net
>                                                                   Subject
>                                       [NLRS] RF Concepts Amp Question
>             11/30/07 03:32 PM
>
>
>
>
>
>
>
>
>
>
>
> Anyone familiar with the RF Concepts Max 45 2m amp?  Its supposed be rated
> for 45w in 150w out according to the manual i got with this one.  I can
> only
> get about 110w output.
>
> Years ago i had a similar model Mirage amp that someone else had 
> readjusted
>
> for 100w output instead of 160w output.  And i remember adjusting 
> something
>
> inside, trimmer caps in the pa if i recall correctly.
>
> I opened this one up and see one large compression trimmer on the input
> side
> of the amp after the T/R relay, and one next to each transistor as well. 
> I
>
> can't find any service information for this model online, as a matter of
> fact i can't find anything for this model online.  Anyone know how to make
> adjustments to this model?  I would like to see it doing at least the 
> rated
>
> output.
>
> The previous owner said it was too much power for him and he turned it 
> down
>
> to 100w according to his wattmeter, mine shows 110w.  Unfortunately he
> doesn't remember what he had to adjust to do that since it was years back.
>
> Thanks in advance...
>
> 73,
>
> Scott KB0NLY
>
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