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- DF1
-
- Ramsey Electronics DF-1 Radio Direction Finder
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-
- The DF-1 Radio Direction Finder allows you to track down hidden or unknown
- radio transmitters using the Phase Difference method.Two antennas are switched
- back and forth rapidly,and if the antenas are not the same distance away from
- the transmitter,a phase modulation is developed in the received frequency.
- This phase modulation can be demodulated on any FM receiver.This demodulated
- siganl is a tone with a specific phase in reference to the rate at which the
- antennas are being switched.As the antenna array is shifted to the left or
- right,the resulting audio also shifts.This shift in phase is detected and
- displayed via a LEFT and RIGHT LED display.
- The construction of the kit is easy,and all parts are included,except
- the case and mounting structure for the antenna array.The Ramsey instructions
- reccomend 1/2 inch PVC pipe for mounting the antenna arrays and the optional
- model CDF case.
- I found an error in the assembly instructions,step #34.The VR1 voltage
- requlator should be mounted with the tab towards the INSIDE of the board,
- not outside as indicated in the assembly instructions.
- The kit functions very well,and has enabled me to locate several noisy
- CATV connections on various telephone poles that were disrupting 2 meter
- reception in my area.
- The DF-1 kit is about $60,matching CDF case is about $13 and the 1/2
- PVC pipe aand TEE connectors and endcaps came out to under $5.
- Total cost for the entire project is about $80 and you end up with a
- valuable tool to locate interference sources,accidental or intentional.
- The address and phone number for Ramsey Electronics can be obtained from
- most any issue of QST,CQ or 73 Magazine.
- Paul,N2MOD @ NY2S.#NLI.NY.USA.NA
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