>Taking everything , via the , what appears to be , a step up ,
>transformer , will provide isolation from the Ae , if
>you combine at
>50 ohms , then everything will pass back to the amps , via the
>combiner ,
...
>Could be totally wrong of course
Any change of the load impedance (R,X) on the secondary side
is seen by the PA on the primary side proportionally to the step up ratio.
>Why not simply build a copy of the Decca out put stage
>, series
>tuned cct's and the 3 -2-1 adding transformer
Perhaps because it is not so easy to get hold of those original transormers and
chokes
within due time?
On the other hand i find that what Andy calls "complicated splitters/combiners"
is not applicable
for the design used by Jay.
What could be simpler than slipping a bunch of easily available toroids over
two pieces of coax
and add a resistor?
73
Clemens
DL4RAJ
>-----Original Message-----
>From: [email protected]
>[mailto:[email protected]] On Behalf Of Graham
>Sent: Saturday, April 15, 2017 6:27 PM
>To: [email protected]
>Subject: Re: LF: Poor aerial connection affecting gate waveforms??
>
>Can only go by the images in the links I sent a while back
>.. I was
>wondering, after Andy's last post ,
>
>Why not simply build a copy of the Decca out put stage
>, series
>tuned cct's and the 3 -2-1 adding transformer
>there must be enough of them about, for the transformers
>and chokes to
>be identified , the same or similar must be about ..
>tried and tested configuration ?
>
>Taking everything , via the , what appears to be , a step up ,
>transformer , will provide isolation from the Ae , if
>you combine at
>50 ohms , then everything will pass back to the amps , via the
>combiner ,
>
>Could be totally wrong of course, but there must of been a
> reason for
>the lay out , when other multi unit pa's used 50 ohm combining
>networks
>but its tried and tested and what's better than 2 500w power
>modules ? .. 3 of course ,)
>
>73-G,
>
>
>
>
>
>--------------------------------------------------
>From: "Chris Wilson" <[email protected]>
>Sent: Saturday, April 15, 2017 3:10 PM
>To: "Graham" <[email protected]>
>Subject: Re: LF: Poor aerial connection affecting gate waveforms??
>
>> Hello Graham,
>>
>> Saturday, April 15, 2017, 2:14:17 PM, you wrote:
>>
>>>
>>>
>>> Chris,
>>>
>>> I assume , due to the Q any small variation , will move the
>>> tune point about , but looking in the data base , Signals ,
>>> better last night to sv8 than the previous night , and may be
>>> up 1 db at pa7 , not to say the noise was less , but at -10 db
>>> that level will be much higher than the local noise level ,
>>> should be a reliable indication
>>>
>>> How important are the wave forms ?
>>>
>>> 73-G,
>>
>>
>> I don't know how important they are I am not a FET ;) All I know is
>> the output transformer and the LP filter bank central toroid
>run a lot
>> cooler if the wave forms aren't all spiky. I hope someone can say how
>> critical this is? Nothing went pop, so presumably not ultra critical,
>> but heat = lost power I would think? Cheers G!
>>
>>
>> --
>> Best regards,
>> Chris mailto:[email protected]
>>
>>
>
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