All it takes to run 700-800W all day long with 572B's is understanding
neutralization and parasitics. The tube itself is as efficient on 6 as HF
and the rest is basics.
Carl
----- Original Message -----
From: "Larry" <n1miw@cox.net>
To: "'Carl'" <km1h@jeremy.mv.com>; <Amps@contesting.com>
Sent: Saturday, July 11, 2009 10:59 AM
Subject: RE: [Amps] Tube choice for SB-200 on 6 meters
> The problem I have is that I do not know what I am doing with these tubes
> for this conversion. I have yet to come across a conversion that everybody
> agrees with. I don't want to be a "hack", I just want to get an amplifier
> on
> the air for 6 meters, do it myself, and not spend an arm & a leg getting
> it
> there. The amp I have was purchased for the right price - I wish it was
> the
> 220 that I had, because of the tubes. However, since I don't, unless
> someone
> can tell me how to do the conversion SAFELY, I would just prefer to change
> the tubes to ones that are rated OK at 50MHZ. Larry N1MIW
>
> -----Original Message-----
> From: Carl [mailto:km1h@jeremy.mv.com]
> Sent: Saturday, July 11, 2009 9:26 AM
> To: n1miw@cox.net; Amps@contesting.com
> Subject: Re: [Amps] Tube choice for SB-200 on 6 meters
>
>
> Obviously I do not want to use the 572B's because of the controversy
> surrounding them at this frequency. TIA... Larry N1MIW
>
>
> There is no controversy among those that know what that are doing. Only
> the
> hacks blow them up and then send the amp to me or others to be done right.
>
> Carl
> KM1H
>
>
>
>
>
>
>
>
> ----- Original Message -----
> From: "Larry" <n1miw@cox.net>
> To: <Amps@contesting.com>
> Sent: Saturday, July 11, 2009 12:34 AM
> Subject: [Amps] Tube choice for SB-200 on 6 meters
>
>
>> Hello group,
>>
>> I'm looking for some information on converting an SB-200 to 6 meters. I
>> originally thought about using the Russian GI-7B tube, but now I'm not
>> sure.
>> It looks like I can only use one tube due to power supply limitations.
>> What
>> have you guys seen in real-world conditions if you used this tube? Will I
>> see about 500 CLEAN watts out from the single GI-7b (someone said in the
>> archives that one of these tubes equals 2 572B's)? Can I use 2 GI-7b's
>> without letting the smoke out of the transformer or PS? There's also the
>> mod
>> for the GLA-1000 where the output watts is ~750 which I'm using for
>> comparison, but I don't know what the current was at that limit. The spec
>> sheet for the GI-7b might put the current for 2 tubes at close to 1A,
>> which
>> the SB-200 can't supply as far as I know.
>>
>> If the single or dual GI-7b can't give me 500 watts+ out from the
>> SB-200
>> PS, is there another tube (or tubes) of choice you would recommend for
>> the
>> SB-200? Obviously I do not want to use the 572B's because of the
>> controversy
>> surrounding them at this frequency. TIA... Larry N1MIW
>>
>> _______________________________________________
>> Amps mailing list
>> Amps@contesting.com
>> http://lists.contesting.com/mailman/listinfo/amps
>
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