[Amps] 4 x Glass Glowing tubes

Mon Feb 27 07:14:26 PST 2012

The typical 5KW AM BCB transmitter of the 50's and 60's used a pair of 
4-1000A's for RF and another pair as modulators.By the 80's most were 
replaced with a 3CX3000A7 RF stage and later SS.

Carl
KM1H

----- Original Message ----- 
From: "Fortra" <fortra at siol.net>
To: "Máximo EA1DDO_HK1H" <ea1ddo at hotmail.com>; <wlfuqu00 at uky.edu>; 
<amps at contesting.com>
Sent: Monday, February 27, 2012 6:44 AM
Subject: Re: [Amps] 4 x Glass Glowing tubes

> Hi Maximo,
>
> i have not heard about 4-1000A being used at AF :)
> But, that is a beast in apperance, definetelly .
>
> Maybe some other European types, such as Philips QB-5/1750,  i know
> the guy who sale them for close to 100,00 Euro., in Croatia.
> Brand new, never used ( military NOS ).
>
> Rgds,
>
> Nermin S58DX
> (Maximo, they used to say :" Real radio's glow in the dark " :)
> Oh well, those were the times, heating, who the hell needs a heating in
> winter !
>
>
> ----- Original Message ----- 
> From: "Máximo EA1DDO_HK1H" <ea1ddo at hotmail.com>
> To: <wlfuqu00 at uky.edu>; <amps at contesting.com>
> Sent: Monday, February 27, 2012 11:37 AM
> Subject: Re: [Amps] 4 x Glass Glowing tubes
>
>
>>
>> Hi all, Bill,
>>
>> Yes, Bill is right.
>> I am not looking for just watts. I don´t want a closed box with ceramic
>> tubes inside (I already own one).
>> What I would like to get is a beauty looking amp with good/high quality
>> audio, based on glass tubes.
>>
>> Let me change the question.
>>
>> What tubes do you recomend to me to build a 14 MHz monoband amp from
>> these; GU48/833A, GU81M or GU5B?
>>
>> GU5b (triode) is powerfull, cheap and AB2 class quality, the only issue 
>> is
>> the blower/noise they need.
>> http://tubedata.tubes.se/sheets/018/g/GU5B.pdf
>> GU81M, tetrode, are cheap, and I guess has quality as well, no blower (or
>> small one), but tetrode needs more power supplies
>> http://tubedata.tubes.se/sheets/018/g/GU81M.pdf
>> GU48/833A, (triode), are cheap, B class, unstable?
>> http://tubedata.tubes.se/sheets/018/g/GU48.pdf
>>
>> It could be just monoband amp, for 14 MHz, may be I can add 7 MHz later
>> on.
>> Thinking in 4 tubes to get blowing glass enough and power between 4 to 10
>> Kw).
>>
>> Any other glass tube?
>> Any recomendation?
>>
>>
>> Thank you very much
>>
>> 73, Maximo
>>
>>
>>
>>
>>
>>
>>> From: wlfuqu00 at uky.edu
>>> To: hsu4qro at gmail.com; ea1ddo at hotmail.com
>>> CC: amps at contesting.com
>>> Date: Mon, 27 Feb 2012 03:03:03 -0500
>>> Subject: RE: [Amps] 833A/GU-48 x4 Amp support
>>>
>>> I believe he wants 4 glowing plates. Larger the better.
>>> 4x 250th would work but a bit expensive compared to the Russan 833.
>>> I once ran 2x 250th in grounded grid driven by a pair of 6146Bs on 20
>>> meters.
>>> So 4 should work.
>>>
>>> 73
>>> Bill wa4lav
>>>
>>> Subject: Re: [Amps] 833A/GU-48 x4 Amp support
>>>
>>> I don't think 833A is a good option.As it have  long  electrode and bad
>>> freqence response. I'm afraid it can not work in 20m in 4X
>>> parallel(self-oscillation).
>>> 3CX3000A7/F7 is better. But if you use ACOM2000A as driver, it will over
>>> drive easily.The drivering power is 400W (max)  for 3CX3000A7/F7. or you
>>> can
>>> use low/ medium  Mu triode
>>> in GG like 3CX3000A1/3CX2500A3..., they need more driving power. Just my
>>> thought.
>>>      73!Hsu
>>>
>>> -----原始邮件-----
>>> From: Máximo EA1DDO_HK1H
>>> Sent: Sunday, February 26, 2012 6:00 AM
>>> To: amps at contesting.com
>>> Subject: [Amps] 833A/GU-48 x4 Amp support
>>>
>>>
>>>
>>> Hi all,
>>>
>>> I am not an amps expert but I am thinking to build an amplifier using 4 
>>> x
>>> GU-48.
>>> I guess GU-48 is equivalent to 833A, not sur if all specs are same.
>>>
>>> This is trying to get an amp "looking beauty" and good audio quality, it
>>> is
>>> not looking for extremely high power. I already have an amplifier (Acom
>>> 2000A) i can use as driver.
>>> Something like this, but HF;
>>> http://www.luxurylaunches.com/entry_images/0511/17/Audio-Power-Labs-833TNT-tube-amplifier-1.jpg
>>>
>>> Gates BC-1g is an example too; http://w5ami.net/bc-1t/833.glow2.jpg
>>>
>>> It could be monoband amplifier for 20m, perhaps 40m too.
>>>
>>> I thought in GU5b and GU-81M before, but I guess GU-48 is better because
>>> needs no specific blower and is triode (easier to build).
>>>
>>> Please, Any of you have sperience with this kind of amplifier?
>>> Any squematic?
>>> Recomendations?
>>>
>>>
>>> Thank you very much
>>>
>>> 73, Maximo - EA1DDO
>>>
>>>
>>>
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>>
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