Kenwood TS-670
This is a cute little QRP rig that covers 40m, 15m, 10m and 6m.
They’re hard to find and they’re even harder to find intact and not-broken.
Overview
- It’s a single conversion radio, 8.83MHz IF
- FM is an add-on (FM-430 module, like the TS-430)
- general coverage receive is an add-on (GC-10)
Weirdnesses
- The Max forward power is first set at 15W, and then tuned for 10W of
voice output
- Then CW (and hopefully FM; still figuring that out) are limited to
10W using a separate pot, rather than also using ALC.
- If you tune the output power max to 10W, then you’ll only ever see
4-5W of max voice power!
- ALC min/max calibration is purely for the meter; there isn’t an ALC
min/max setting based on the voice input. The only feedback into the
ALC line comes from the forward power pot and associated circuitry.
Known Schematic/PCB Differences
-
I’ve found that C61 and R31 on the control board are inverted on
the PCB - C61 goes to the junction of L28/R32, then the ground of C61
goes to R31, that then goes to ground
-
The two pairs of resistors in the TX mix on the RF board are indeed
crossed on the PCB; the silk screen and layout is wrong!
Revisions
(TBD)
Common Issues
(TBD)
PDFs
The service and user manuals should be used together to figure out
what’s going on.