[Amps] SRS 360?

[Jim W7RY]

- 80 volts bias on a SB-220?  Last time I looked at a SB220 the bias was 
provided by a 5 volt zener diode.


How about -80 volts is what the SB-220 uses to cut off the tube during 
standby?


73
Jim W7RY

----- Original Message ----- 
From: "Carl" <km1h at jeremy.mv.com>
To: "Karl-Arne Markström" <sm0aom at telia.com>; "Paul Gerhardt" 
<phgerhardt at gmail.com>; <amps at contesting.com>
Sent: Sunday, November 01, 2009 6:17 AM
Subject: Re: [Amps] SRS 360?


> 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
>>>
>>> _______________________________________________
>>> Amps mailing list
>>> Amps at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>
>>
>> --------------------------------------------------------------------------------
>>
>>
>>
>> No virus found in this incoming message.
>> Checked by AVG - www.avg.com
>> Version: 8.5.423 / Virus Database: 270.14.39/2470 - Release Date: 
>> 10/30/09
>> 15:18:00
>>
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - www.avg.com
Version: 8.5.423 / Virus Database: 270.14.37/2466 - Release Date: 10/28/09 
19:39:00