----- Original Message -----
Sent: Monday, April 04, 2005 7:44
PM
Subject: LF: Fw: TX cores / current
sensors
----- Original Message -----
Sent: Monday, April 04, 2005 2:01 PM
Subject: TX cores / current sensors
To the members on the LF group
,
As I am trying to draw the circuit
diagram of a recently bought Ropex "The First " transmitter I found the
following interesting detail . The output current of the TX is passing 3
paralelled 1 Ohm resistors to the antenna-relay , the voltage developped
over this resistance is coupled to the input of a optocoupler IC which is
connected to the protection circuit . As optocouplers are normally well
insulated at least a few Kv this idea must be suitable for lots of
applications .
As a new member of the group I wish
to join you and have as much pleasure from it as my radiofriend Dick PA0SE who
fixed my attention on your group .
73,William PA0WFO ( hope to work you
in the near future )
A couple of bits of info that I have
concerning the above Ropex TX.
The Pa Fets are IRF1010N, the drive
is a SG3525 device and the xtal is 6.5536 khz.
If u get the cct sorted out I could
do with a copy. I do have a ROPEX although I have never really used it except
for testing out hi, but it would be useful as an emergency
TX.
One other thing, it will not load
into a grounded loading coil on High PWR and to overcome this problem use a
LPF and then it works FB.
73 De
Mal/G3KEV
