[Amps] filament transformers

[Bob Maser]

Carl, I'm beginning to think that everything I've read about you on the 
reflector is true.  You make a derogatory comment about W4LNI and now you 
say "leave me out of it".  Give me a break.

Bob W6TR
----- Original Message ----- 
From: "Carl" <km1h at jeremy.mv.com>
To: "Bob Maser" <bmaser at tampabay.rr.com>
Sent: Friday, May 15, 2009 10:53 PM
Subject: Re: [Amps] filament transformers


> Leave me out of the middle, its not my problem
>
> I dont know your friend.
>
> Carl
>
>
> ----- Original Message ----- 
> From: "Bob Maser" <bmaser at tampabay.rr.com>
> To: "Carl" <km1h at jeremy.mv.com>
> Sent: Friday, May 15, 2009 10:42 PM
> Subject: Re: [Amps] filament transformers
>
>
>> Your friend was not telling you the truth.  Jim is very reliable and a 
>> straight shooter.  One time he built a filament transformer for a 
>> 3CX1200D7 for me and the transformer delivered slightly higher voltage 
>> than I wanted. No questions asked, he built me another for no additional 
>> charge and added extra primary taps.  I'll forward you e mail to him for 
>> his info.
>> Bob
>> ----- Original Message ----- 
>> From: "Carl" <km1h at jeremy.mv.com>
>> To: "Bob Maser" <bmaser at tampabay.rr.com>; "Paul Decker" 
>> <kg7hf at comcast.net>; <amps at contesting.com>
>> Sent: Friday, May 15, 2009 10:20 PM
>> Subject: Re: [Amps] filament transformers
>>
>>
>>>A friend recently got stiffed from that source for an 8877 filament xfmr, 
>>>it was almost $100. He didnt think to check out the $33 Hammond.
>>>
>>> Carl
>>> KM1H
>>>
>>>
>>>
>>>
>>> ----- Original Message ----- 
>>> From: "Bob Maser" <bmaser at tampabay.rr.com>
>>> To: "Carl" <km1h at jeremy.mv.com>; "Paul Decker" <kg7hf at comcast.net>; 
>>> <amps at contesting.com>
>>> Sent: Friday, May 15, 2009 7:36 PM
>>> Subject: Re: [Amps] filament transformers
>>>
>>>
>>>> Waste money on a custom filament transformer? I'm not talking about a 
>>>> $100 transformer, maybe $35.  If you can't afford that maybe you 
>>>> shouldn't be building homebrew amps.
>>>>
>>>> Bob W6TR
>>>> ----- Original Message ----- 
>>>> From: "Carl" <km1h at jeremy.mv.com>
>>>> To: "Paul Decker" <kg7hf at comcast.net>; <amps at contesting.com>
>>>> Sent: Friday, May 15, 2009 6:58 PM
>>>> Subject: Re: [Amps] filament transformers
>>>>
>>>>
>>>>> Get the 3A version and measure the voltage at the socket. If its high
>>>>> (which it should be) wind some wire on a small ferrite rod which can
>>>>> also double as a filament choke. When you go to the 2nd tube use 
>>>>> heavier
>>>>> wire on the rod or none depending on the voltage. It never hurts to go
>>>>> slightly lower than the median spec.  The transformer will only give 
>>>>> 14V
>>>>> at its 3A rating and it will be a bit higher at 1.5A
>>>>>
>>>>> Dont waste money on an overpriced custom transformer in this instance. 
>>>>> I
>>>>> dont see the necessity for a rheostat either for such a small drop.
>>>>>
>>>>> Carl
>>>>> KM1H
>>>>>
>>>>>
>>>>>
>>>>> ----- Original Message ----- 
>>>>> From: "Paul Decker" <kg7hf at comcast.net>
>>>>> To: <amps at contesting.com>
>>>>> Sent: Friday, May 15, 2009 4:40 PM
>>>>> Subject: [Amps] filament transformers
>>>>>
>>>>>
>>>>>>
>>>>>>
>>>>>> Hello builders,
>>>>>>
>>>>>>
>>>>>>
>>>>>> My amp continues to grow. I'm trying to pick out a filament
>>>>>> transformer, such and easy task.
>>>>>>
>>>>>>
>>>>>>
>>>>>> The amp is based on a 3cx800a7 which requires 13.5V +- 0.6V at 1.5A. 
>>>>>> I
>>>>>> was thinking that a 14V transformer would work great. Ideally, I 
>>>>>> would
>>>>>> like to build the amp with the option to eventually be expanded to a
>>>>>> pair of 3cx800's rather than the single. This would mean I need 3.0A
>>>>>>
>>>>>>
>>>>>>
>>>>>> On digikey , they have a 14V 3.0A transformer
>>>>>>
>>>>>> http ://search. digikey .com/scripts/ DkSearch / dksus . dll
>>>>>> ?Detail&name=237-1279-ND
>>>>>>
>>>>>>
>>>>>>
>>>>>> and a 14V 4.0A transformer
>>>>>>
>>>>>> http ://search. digikey .com/scripts/ DkSearch / dksus . dll
>>>>>> ?Detail&name=237-1094-ND
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> So my questions are: Is it acceptable to use the higher current 
>>>>>> rating
>>>>>> in the single tube version of the amp? Would current inrush be an
>>>>>> issue? Is the 3A version enough, should I get the 4A version or
>>>>>> something even larger? Or, is there something else I should be
>>>>>> thinking about using?
>>>>>>
>>>>>>
>>>>>>
>>>>>> thanks,
>>>>>>
>>>>>> Paul, kg7hf
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> 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
>>>>
>>>
>>
>