Component changes on the v6 RXTX
- Good Evening All,
A number of people have contributed to coming up with a solution for
the low power output and out of spec spurious emission with the v6
RXTX as well as with the prototype exciter board pair. Jan,(G0BBL),
Bodo,(DJ9CS), and Terry, (WB4JFI)have been especially helpful and
involved in making the v6 RXTX board meet FCC specs.
The small kit of parts that I will be sending to each of the v6 RXTX
kit buyers will cover the following component changes to the board:
1) R1 and R7 changed to 22.1k resistors.
2) 100 ohm resistors are placed in series with each of the two T1
leads that connect to pins of U3.
3) R21 is reduced to 10 ohms.
4) RFC1 is removed from the circuit and a 100 ohm resistor is put in
the RFC1 location.
5) Components in the LPF on the output of Q2 are changed to the
C26 = C30 = 470pF, C28 = 820pF, C27 and C29 are not used, L4 and L5
are each 1.1uH, (17 turns on a T30-2 core).
With the above changes Terry and I are each getting at least 400 mW
of "clean" RF output.
I will start send out the kit of parts needed to make these
changes. I would like to send the needed parts to people who have
sent me an e-mail listing any parts that were missing or broken in
the their kit according to the most recent bill of materials. This
will save mailing twice to supply missing parts as well as the
I will post a similar list of changes for the prototype exciter kit
in the morning.
Thanks and 73,