[Amps] SRS 360?

[Carl]

Interesting site, however no mention is made of IMD performance with the 
TB3/750 which is NOT a zero bias tube as claimed.

As a Class B GG 3-500Z replacement in say a SB-220 a bias of 
approximately -80V is required with a resultant 180-200 ma idle current. 
For a much cleaner signal AB2 a ~ -50V bias is required with a resultant Ip 
of over 500 ma for the pair! At 2500V this is approaching the Pd of the 
tubes resulting in excessive transformer and tube heating for the cooling 
fan under even moderate SSB use. An electronic bias circuit would just about 
be mandatory.

In addition a completely redesigned input circuit is needed along with 
sufficient drive to overcome the bias.

If a clean signal is of importance then the TB3/750 or 5867 is not an 
acceptable tube for SSB at typical 3-500Z plate voltages.

Carl
KM1H



----- Original Message ----- 
From: "Karl-Arne Markström" <sm0aom at telia.com>
To: "Carl" <km1h at jeremy.mv.com>; "Paul Gerhardt" <phgerhardt at gmail.com>; 
<amps at contesting.com>
Sent: Sunday, November 01, 2009 3:47 AM
Subject: Re: [Amps] SRS 360?


> The SRS360 was the DDR manufactured equivalent of
> the TB3/750 or  5867A.
>
> It is a 350 W dissipation medium-mu triode which needs a bias circuit to 
> work properly.
>
> An RF amplifier circuit using the TB3/750 can be found at
>
> http://www.xs4all.nl/~pa0fri/Lineairs/Frinear750/FRI750uk.htm
>
> 73/
>
> Karl-Arne
> SM0AOM
>
>
> ----- Original Message ----- 
> From: "Carl" <km1h at jeremy.mv.com>
> To: "Paul Gerhardt" <phgerhardt at gmail.com>; <amps at contesting.com>
> Sent: Saturday, October 31, 2009 10:21 PM
> Subject: Re: [Amps] SRS 360?
>
>
>> Ich bien be usen en infernalmachen.
>>
>> Looks like an Amperex 5868 clone or similar. Industrial class C tube; 
>> good
>> for Class B audio also.
>>
>> Carl
>> KM1H
>>
>>
>>
>>
>> ----- Original Message ----- 
>> From: "Paul Gerhardt" <phgerhardt at gmail.com>
>> To: <amps at contesting.com>
>> Sent: Saturday, October 31, 2009 5:10 PM
>> Subject: [Amps] SRS 360?
>>
>>
>>> Do these ever get used in Amateur service?
>>>
>>> Looks like a 3-500z
>>>
>>> http://www.radiomuseum.org/tubes/tube_srs360.html
>>>
>>> ?
>>>
>>> Paul K3PG
>>>
>>>
>>>
>>> -- 
>>> Paul Gerhardt
>>> K3PG
>>> http://pgerhardt.blogspot.com
>>> QRP ARCI 6674
>>> FP 274
>>> _______________________________________________
>>> Amps mailing list
>>> Amps at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>
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>
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