with R3 to the junction with the battery positive point. Because the resistance of the photocell changes according to how much light is present, this will cause the audio tone to change as well. In the same way you can try placing a thermistor either across R4 or in place of it (depending on the value of the thermistor). Thermistors are devices whose resistance changes depending on temperature. Be creative! Experiment! That’s what Ramsey kits are all about.
CHANGING YOUR CRYSTAL
It is possible to change the frequency of your MR6 kit in two ways. The first is to change the value of C12. Increasing or decreasing the value of C12 will cause the circuit to oscillate at a slightly different frequency. Remember that you’ll still be in the 2 meter band, since that’s what the kit was designed for. The other way to change the frequency is to change the crystal. The sche- matic shows the different multiplication factors for different common crystals. If you need to order a crystal, one of the places you can call is Jan Crystal at
CONCLUSION
We sincerely hope that you have enjoyed the construction and use of this Ramsey Kit. As always, we have tried to compose our manual in the easiest, most “user friendly” format that is possible. As our customers, we value your opinions, comments, and additions that you would like to see in future publications. Please submit comments or ideas to:
Ramsey Electronics Inc.
590 Fishers Station Drive Victor, NY 14564
And once again, thanks from the folks at Ramsey!
MR6 • 14
