User manual RAMSEY FHT1

[. . . ] This kit combines a crystal locked true FM transmitter with a microprocessor for reliable operation. Multiple transmission "modes" assure a "sly fox" that will challenge any fox hunter. · · · · · · · · · · Selectable high (5W) or low power (800 mW) operation - unit can even be programmed to change power levels during use!Can even generate a 1 KHZ tone to "fool" Doppler type direction finders!Add optional electronic VOICE ID CIRCUIT for harassment messages - up to 20 seconds, "Ha, ha you can't find me!" Informative manual answers questions on theory, hookups and uses - enhances resale value, too! FHT-1 · 1 RAMSEY TRANSMITTER KITS · FM-10, FM-25 FM Stereo Transmitters · FM-1, 2, 4 FM Wireless Microphones · PB-1 Telephone Transmitter RAMSEY RECEIVER KITS · FR-1 FM Broadcast Receiver · AR-1 Aircraft Band Receiver · SR-1 Shortwave Receiver · AA-7 Active Antenna · SC-1 Shortwave Converter RAMSEY HOBBY KITS · SG-7 Personal Speed Radar · SS-70 Speech Scrambler · TT-1 Telephone Recorder · SP-1 Speakerphone · MD-3 Microwave Motion Detector · PH-10 Peak hold Meter · LC-1 Inductance-Capacitance Meter RAMSEY AMATEUR RADIO KITS · FX Series VHF and UHF Transceivers · HR Series HF All Mode Receivers · QRP Series HF CW Transmitters · CW-7 CW Keyer · PA Series VHF and UHF Power Amplifiers · Packet Computer Interfaces · QRP Power Amplifiers RAMSEY MINI-KITS Many other kits are available for hobby, school, Scouts and just plain FUN. [. . . ] This "voltage divider" is tied to the base of Q8, the power PNP transistor, forward biasing Q8 and supplying 12VDC to the final transistor, Q6. Conversely, when there is no voltage applied to Q7, both Q7 and Q8 are turned "off", and the current must flow through resistors R18 and R19. The voltage drop across these resistors causes less potential to be applied at the collector of Q6, lowering the output power. Note to more experienced kit-builders The "low power" setting can be adjusted by changing the values of R18 and R19. Please keep both values the same (for equal power dissipation), The higher the total value - remember that these resistors are in parallel - the lower the RF output power will become. Please use at least one watt resistors for this modification. FHT-1 · 18 Also there is a provision to adjust the "high power" output. Notice that jumper J5 connects the collector of Q8 to the final transistor Q6. by removing this jumper and installing a suitable resistor (remember to calculate the power dissipation) the high power output can be lowered from its full 5 watt value. Heavy buss wire jumper (not a scrap component lead) Wire sits flat against board PC board 1/2 inch Please understand that these modifications should not be attempted unless you are experienced enough to calculate the current and power yourself and they are not recommended until after the entire unit has been fully tested. The testing instructions are intended for the existing unmodified kit. As long as we're stopped already, now would be a good time to recheck your work, focusing on parts placement and soldering. Resolder any connections that are less than perfect, and trim all the leads to a reasonable length. Remember that this capacitor is polarized, so be sure to orient it correctly. Turn over the PC board and set the transistor snugly into the large hole and bend the leads over and into the indicated holes. The leads should be as short as possible without shorting against the transistor case. Now we call for something unusual - soldering the transistor case to the PC board. Run a neat "flow" of solder around the gold transistor FHT-1 · 19 case to the PC board ground plane. The SD1127 power transistor is designed by the manufacturer to be soldered directly to a PC board ground plane for heat sinking and proper VHF performance. This part is different from other metal can transistors in that the case is connected internally to the emitter rather than the collector. Prepare an ½ inch long wire jumper from the heavy tinned bus wire used for winding coils previously. Believe it or not, this wire is actually an inductor providing impedance matching into Q6. Ensure that the coil is seated flush against the PC board and not mounted with long leads up in the air - which would add undesired additional inductance. You've completed most of the RF output section of the Sly Fox transmitter. [. . . ] The oscillator values is suitable a tripler it is a critical value such as a on a stepor IC, or whether a RANGE of is followed by (such as stage, and 3 Often times, common sense will solve a mysterious missing part problem. Once again this signal you're missing five 10K a nearby receiver such as a 1K resistors, One more triplerbe assured be tuned on ohm resistors and received five extra scanner. you can pretty much follows that the '1K ohm' resistors are actually the 'missing' 10 K parts ("Hum-m-m, I guess the 'red' band really and that moves us up to the final 146. 520 MHz output frequency, easily does look orange!") Ramsey Electronics project kits are packed with pride in the USA. This part clearly indicated in your to the manual as supplied we packed an incorrect part or omitted a procedure will lead usassemblyfinal amplifier with the basic kit by Ramsey, pretty write or call us with information on the part you need and proof of stages where we can please much do a thorough visual inspection. [. . . ]