[Moon-net] [Re: TS-950SDX and transverter problem]

[Alexandr Kobranov]

We have to sort out if there is wrong internal ALC voltage generator (in 
such case the same problem - or worse - on any HF band with full power 
to 50ohm load) or if there is some problem with ALC "timing" only during 
R/T transient period.
In some cases/equipments there is useful to use external ALC input to 
apply some minus voltage (9V battery, 7805 stabilisator and small pot. 
trimer) to force ALC voltage to tcvr independently on internal 
adjustaments (Power knob etc...). As I remember such thing helps in 
FT-847 setup and should work +/- on any gear. And there is sure that if 
somebody turns RF Power to maximum on front panel by mistake, this 
external ALC will block power increase on output from TCVR.
I suppose that in such setup there should be no peak on R/T switching, 
if still there something wrong gerally...

Another problem is switching system in some transvertors - low power 
switching PIN diode was not able to handle "peaks" problem or operators 
fails - after this one was changed to some 20W version (MI308 if my 
memory is working) this problem never appeared back. (Talking about 
driving on 144MHz when max.power from I/F tcvr is between 20-50W).

73!
Lexa, OK1DST


f6dro napsal(a):
> Hi Carsten.
> I don't own a TS950 , but I own a TS850. I got the same pb on my TS850 and 
> it is a very common problem , so maybe it is the same on the 950. On some 
> web pages , you will see some recomandations abt changing the ALC voltage 
> generator board , but in fact the cure is very easy : U need to change 2 
> resistors.
> So check:
> http://n6tr.jzap.com/850repair.html#ALC_voltage_problem
>
> in case ALC generation is the same for TS950
> best 73 Dom/F6DRO 
>
>
>
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