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Parts required for conversion to 6 Meters for the Transmitter PA PCB:
Parts for Midland 70-066
Capacitors.
4.7pF
- 1 of
22
pF
- 2 of
27
pF
- 2 of
33
pF
- 1 of
39
pF
- 2 of
100
pF
- 1 of
1000
pF
- 1 of
Wire.
Approximately 200 mm of 0.63mm [22bs] enameled coated wire [Jaycar WW4018].
NOTES:
1: Use the proper power meter to measure the output power. For example, if you use a 140 to 525Mhz
power/SWR meter – you will get false readings. Such as 6 watts instead of 25 watts.
2: The voltage applied to the PA stage will determine your output power. Eg
25 Watts with 12.0 Volts
38 Watts with 13.8 Volts
3: It has been noticed that some converters have accidentally removed a, or some Surface Mounted
Components while de-soldering coils etc from Printed Circuit Boards.
This has resulted in circuits not tuning correctly or, especially the PA board self oscillating on
another frequency other than the 6 meter band.
Especially look at the Surface Mounted capacitor across CV502. You will have to check with the
Midland Service Manual.
Also remember to have capacitor legs as short as possible. When bending the capacitors over, make
sure that the legs have not shorted onto the board.
4: At this point in time, it looks like the following amendment will be necessary for the capacitor
across CV502:-
22pF for Midland 70-066A
33pF for Midland 70-066B
Midland 70-066 low Band Conversion to 6 Meters: Transmitter PA Part 4 Ver 2.2 21Nov09 Page 1
Jaycar
RC-5308
Note:
RC-5316
RC-5217
RC-5218
RC-5219
RC-5324
RC-5336
All capacitors are 50V Ceramic
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