Carl wrote:
> What spec sheets from what manufacturers?
>
> Please cite actual examples.
>
> Carl
> KM1H
>
>
> ----- Original Message -----
> From: "KB0NLY" <kb0nly@mchsi.com>
> To: "Carl" <km1h@jeremy.mv.com>; "David Craig"
> <davidhcraig@verizon.net>; <amps@contesting.com>
> Sent: Friday, March 13, 2009 11:36 AM
> Subject: Re: [Amps] SB200 on 6m & my take
>
>
>
>> Since all the spec sheets from all the manufacturers said so. They
>> hardly hold their own at 10m.
>>
>> 73,
>>
>> Scott
>>
>>
>> ----- Original Message -----
>> From: "Carl" <km1h@jeremy.mv.com>
>> To: "David Craig" <davidhcraig@verizon.net>; <amps@contesting.com>
>> Sent: Friday, March 13, 2009 8:45 AM
>> Subject: Re: [Amps] SB200 on 6m & my take
>>
>>
>>
>>> I'll be briefer. Since when isnt the 572B rated to 6M?
>>>
>>> Carl
>>> KM1H
>>>
>>>
>>> ----- Original Message -----
>>> From: "David Craig" <davidhcraig@verizon.net>
>>> To: <amps@contesting.com>
>>> Sent: Friday, March 13, 2009 12:44 AM
>>> Subject: [Amps] SB200 on 6m & my take
>>>
>>>
>>>
>>>> Brief & to the point- they stink, monoband or (worse) tapped
>>>> bandswitch "models". They may be fine for the occassional SSB QSO
>>>> without pushing it, but otherwise they do one thing with regularity-
>>>> they die/burn out/self-destruct. RTTY? WSJT & other digicrap with
>>>> 100% duty cycle for 30-55 seconds key-down? Result? Be ready for a
>>>> buzz, hiss, POP & Boom & to buy a new amp, or parts that cost enough
>>>> $
>>>> to build a new one. I don't do any digital myself save cw but if
>>>> you
>>>> want a list of dead SB200 conversions (owned by others) I'll be
>>>> happy
>>>> to provide them, some were EME deaths & others that just "crapped
>>>> out"
>>>> due to tubes that aren't ment to be used at that QRG.
>>>> I don't care what you can "get away with", I want something that
>>>> isn't going to crap out because the tubes aren't rated for 50MHz
>>>> use.
>>>> SB200s should be left to HF. If you are still going to convert one,
>>>> do what I am doing and put a 3CPX800 in it with new cooling and a
>>>> new
>>>> FWB PS and appropriate transformer. Otherwise build one with an
>>>> appropriate tube/s from scratch which I have also done x 3. 572Bs
>>>> are
>>>> a lousy tube for 6m conversion unless your habit is to run it a few
>>>> hours per year.
>>>> Oh, one last thing- for parasitic suppressors, don't be lazy and
>>>> use the resistor leads as a soldering surface for the L (really a
>>>> "U")
>>>> between resistor sides on a 6m conversion. I have seen 4 cases so
>>>> far
>>>> of that method resulting in heat melting the "L" on the plate-block
>>>> side... ergo all B+ plus RF current passes thru the resistors &
>>>> softens the tubes in seconds. $600+ $ down the tubes.
>>>>
>>>>
I'll chip in... Svetlana, kind of old (I saved a PDF of it in 2001)
30mHz
Bill N2BC
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