Heathkit HW-8 Mods Information

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This mod allows you to read your actual transmit and receive frequency of the HW-8 with an OHR DD-1 Digital dial or any general-purpose counter.

The following is a simple circuit I developed for driving my OHR DD-I Digital Dial from my HW-8. I found that trying to take the output off the VFO directly and several other places resulted in the counter clock getting into the receiver or the counter being sensitive to RF when the rig was keyed. The circuit was built on a piece of perf board and mounted on the inside back of the cabinet. Mount C1 on the circuit board at the junction of R49 and R 51. It is also important you use good shielded wire from C1 to the input of the buffer. It is also important that the shield be grounded at both ends. I found the lug attached at the VFO capacitor made a good ground for the shield at the input end. The output of the circuit should be mounted as close as possible to J1, again use good shielded wire grounded at both ends.
 

The circuit uses a general purpose npn transistor, a 2N2222 or Radio Shack generic works fine. Make sure to use good shielded wire to bath the input and output. The input shield is grounded on the tuning capacitor; the output shield is grounded on the back of the case where a RCA phono jack used to provide output to the counter.
 

72/73,

Steve Ray K4JPN ex K1VKW HW-101, HW-8,

SWL 30-40, Pixie II, NC 38S, OHR 100A 30 M and Heath Kit fan