|
To Mal and the rest of
the members of the LF group
Tnx for your warning
about the protection of the finals Mal . In my case the 1010,s did not
explode without proper drive but only made a lot of noise in the receiver while
practically not taking any input current . But that propably will not be so in
all cases . So just to be sure I will make a protection circuit which prevents
the keying ( or uses the protection circuit ) of the transmitter . In my
transmitter the 1010,s are originally fitted and as far as
I can check all the late versions of the Ropex have them fitted
. Because the firm who was selling the transmitters ( maybe also producing them
) went out of business recently a lot of these sets ( 25 ) were sold for very
low prices ( less then 30 Euro,s ) . I hope to work the buyers with manual CW in
the near future .
73 to all of you
William
PAØWFO
----- Original Message -----
Sent: Sunday, May 22, 2005 5:39 PM
Subject: LF: Re: Modification of the blower circuit and VFO drive
for the ROPEX LF TRANSMITTER
William you forgot to say, the PA
explodes without drive !!!!!!!!!!!!!! not just TAKES OFF
The pa fets in my model are IRF1010N,
maybe they have already been changed before !!
A protective cct is necessary so that the
the TX cannot come on except there is already drive. I have such a cct on my
home built TX as a precautionary measure.
Ropex modification operators beware
because if the switch got moved accidentally from the Xtal position and there
was no drive via an ext VFO you will end up with a heap of
ashes!!
Beware de MAL/G3KEV
You can prevent this by leaving the
switch out and just connect the VFO to terminal 10 off the oscillator ,
more or less as in Dicks PAØSE transmitter ( described in the LF experimenters
handbook ) with the slight disadvantage that you cannot use the VFO on
the Xtal frequency .
73,William
PAØWFO
| 