[hpsdr] Re Munin low output on 6m

[Kjell Karlsen]

Hi Al.

It seems as if the compensation of the output transformer might be  
different with the type of wire you have used compared with what I used.  
You may try to remove one of the capacitors and try again to see if it is  
worse or better.

Can you please measure the wire diameter and the outer diameter of the  
insulation.

I´ll test with the VNA when I come home next week. At the moment I am in  
Spain for a short holiday.

73, Kjell





På Fri, 22 Nov 2013 17:50:09 +0100, skrev a.groff <k0vm at mchsi.com>:

> Kjell,
>     Replacing the Capacitors and I can now get 115 watt at 50mhz and a  
> bit more at 53mhz.
>
>     However, at 28mhz I can only get 90 watts and less at  30mhz .. ( a  
> lot less at 42 mhz ).
> It appears to start going into saturation at about 75 watt at 28mhz.   (  
> I had 100+w at 28 before replacing the capacitors.)
>
>    I think I shall try tightening up the turns on L4  (??? ) if your  
> think that would help.
>
> AL, K0VM
>
>
>
>
> On 11/16/2013 11:04 AM, a.groff wrote:
>> Kjell,
>>    I have the Caps on order and will report back..
>>    If the problem is in the final output transformer shouldn't the t1-2  
>> source current increase as driver is increased above saturation ??
>>    At 40watts output ( below saturation ) the drive required for 40  
>> watts out is basically flat from 160m thru 6m.
>>
>> AL, K0VM
>>
>>
>> On 11/16/2013 3:30 AM, Kjell Karlsen wrote:
>>> Hi Al.
>>>
>>> I agree that the problem might be one of the capacitors. All my  
>>> problems with low power on 6 meter has been with the output  
>>> transformer and components around it.
>>>
>>> Please report back when you have tested with new capacitors.
>>>
>>> 73, Kjell
>>>
>>>
>>>
>>>
>>>
>>> På Sat, 16 Nov 2013 00:33:28 +0100, skrev Bob Campbell  
>>> <joan-bob at bigpond.net.au>:
>>>
>>>> ***** High Performance Software Defined Radio Discussion List *****
>>>>
>>>> Hi Al,
>>>>
>>>> Check caps C25 C26 C27 are all ok.
>>>>
>>>> Mine failed when I went to load it up on 6m, blew the cermic cap  
>>>> apart.
>>>>
>>>> As Kjell suggested in a previous post replace these caps with four  
>>>> 220pf
>>>> 500vw 1206 caps.  Since doing this mine has been ok.  I suspect with
>>>> this mod the current is shared evenly between all 4 caps and the  
>>>> circuit
>>>> is much more stable and I have no trouble getting the desired output  
>>>> on
>>>> 6m now.
>>>>
>>>> 73's
>>>> Bob.c
>>>> Vk4xv
>>>>
>>>> _______________________________________________
>>>> HPSDR Discussion List
>>>> To post msg: hpsdr at openhpsdr.org
>>>> Subscription help:  
>>>> http://lists.openhpsdr.org/listinfo.cgi/hpsdr-openhpsdr.org
>>>> HPSDR web page: http://openhpsdr.org
>>>> Archives: http://lists.openhpsdr.org/pipermail/hpsdr-openhpsdr.org/
>>>>
>>>>
>>>
>>>
>>
>>
>
>


-- 
Sendt med Operas e-postklient: http://www.opera.com/mail/

 1385149248.0