Quick 1-Radio QSY If you canīt afford an automatic linear such as an Alpha87 or Acom2000 and you do not like adding a second station, then the simple circuit shown in Fig. 1 may be a good option.
Fig. 1  |
All you need is 2 or more non-automatic linears which you pretune for separate bands and select when QSYing. You may either use handswitching of both the HF- and PTT-paths or build a little flip-flop switching circuit as indicated above. Even with only 2 linears you will save a great amount of time when changing bands as you will - for example - most likely toggle between 10/15m during daytime and 40/80m during nighttime requiring only occasional tuning. Besides, this operating style is light to your linears as they have time to recover when not in use. If your radio supports 2 antenna ports (e.g. TS870) it will do all the switching - except PTTīs. Borrow 1 or 2 additional SB220īs for a contest weekend and work those packet spots before your competition does!
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