Sockets in use are Eimac SK-640.
73, Roger
AI7RR
On Mon, Jul 27, 2015 at 10:49 AM, <donroden@hiwaay.net> wrote:
> I woke up and the thing on my mind was .....
>
> Are you using Eimac SK-630 sockets ?
>
> I think those sockets may have been the reason my amp was so stable on six.
>
>
> Don R.
>
>
>
> Quoting Roger <ai7rogerroger@gmail.com>:
>
> Don,
>> Thank you for the information. I've been studying other circuits and
>> combined with the info you just mentioned regarding screen loading, I have
>> a change to make. Both my grid and screen supplies are very stiff with
>> capability of supporting reverse current. My screens however are shunted
>> with very high resistance at the terminals just to hold them at ground
>> during rx.
>>
>> I've gone through many different wiring configurations with this amp and
>> have even had output once or twice, but every time I try to improve it, I
>> screw something up. This time finding the error hasn't been so easy.
>>
>>
>> 73, Roger
>> AI7RR
>>
>> On Sun, Jul 26, 2015 at 8:17 PM, <donroden@hiwaay.net> wrote:
>>
>> No problem... Just think of the 250Bs as a big variable DC load on the
>>> plate power supply. You should be able to change the grid voltage and
>>> see
>>> a smooth
>>> increase in plate current from zero to near 1000ma ( very briefly !!! )
>>>
>>> I would suggest zero to 500ma as a minimum range to check.
>>> No more than that until absolutely sure everything is stable
>>>
>>>
>>> THEN hook up the grid circuit and see if you can do the same thing..
>>> something may be breaking down in the grid circuit and killing the bias
>>> voltage and
>>> then ...... BOOM ... Plate current runs away.
>>>
>>>
>>>
>>>
>>>
>>> Quoting Roger <ai7rogerroger@gmail.com>:
>>>
>>> "I'm confident my DC is stable."
>>>
>>>>
>>>> Scratch that. I misunderstood the statement:
>>>>
>>>> "He has to make the amp DC stable before hooking up the input and output
>>>> RF
>>>> networks."
>>>>
>>>>
>>>>
>>>>
>>>> 73, Roger
>>>> AI7RR
>>>>
>>>> On Sun, Jul 26, 2015 at 5:50 PM, Roger <ai7rogerroger@gmail.com> wrote:
>>>>
>>>> Sorry, I thought it was clear what I was trying to do. I have four
>>>> 4x150a
>>>>
>>>>> tetrodes in parallel, attempting to make them operate on 50mhz. I'm
>>>>> confident my DC is stable. Additional information includes, a Pi tuned
>>>>> input and output. Input and output terminations are quality 50 ohm
>>>>> devices.
>>>>> Power supply and rf deck are in separate boxes. My problem appears to
>>>>> be
>>>>> related to instability possibly caused by insufficient or incorrect
>>>>> neutralization.
>>>>>
>>>>> It was mentioned that the neutralizing cap needed to be by-passed and
>>>>> that's something I have not even considered. By-passing anything in the
>>>>> grid circuit seems contradictory to me.
>>>>>
>>>>>
>>>>> 73, Roger
>>>>> AI7RR
>>>>>
>>>>> On Sun, Jul 26, 2015 at 3:56 PM, <donroden@hiwaay.net> wrote:
>>>>>
>>>>> Quoting Ron Youvan <ka4inm@gmail.com>:
>>>>>
>>>>>>
>>>>>>
>>>>>> I am trying to find out what you are trying to do.
>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> Me Too Ron,
>>>>>>>
>>>>>>
>>>>>> He has to make the amp DC stable before hooking up the input and
>>>>>> output
>>>>>> RF networks. We don't know if that's the case yet.
>>>>>>
>>>>>> Don W4DNR
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> Amps mailing list
>>>>>> Amps@contesting.com
>>>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|