TR-1b RF T/R Relay Board......$25, two for $40
This board allows you to switch the antenna between the transmitter and receiver as well as up to 1 Amp DC with another relay at the same time. The RF relay will switch up to 25 Watts at 70cm. Two of them can be used to switch an amplifier in or out. While the DC relay can only handle up to an Amp, most power modules final DC power can be left on and the bias voltage switched instead. The board mounts on a chassis mount type N UG-58 or SO-239 50 Ohm RF jack. See the TR-1b data sheet and PA5-20 ATV amplifier application note using the RA30H4047M power module.
TXTVb ATV Exciter/Modulator Board...$30
Make a low cost 70cm ATV RF Test Generator for tuning up receivers or antennas. Demonstrate ATV at a ham club, Scout Jamboree, Field Day, etc., with this unit - transmit in the building to a cable ready TV set. This board puts out about 10 mW and uses the same crystals as found in all our 420-450 MHz ATV transmitters.. The board comes partially built (as shown in the photo) and with all 12 of the additional parts as a kit to complete the board. Assembly and tune up instructions using a DC Voltmeter are included - download and see the data sheet by clicking on the board photo above.
Or, by using a different crystal and additional parts kit, you can drive a 2 meter in / higher band out Transverter like those available from Downeast Microwave, SSB and others, you can add the AM ATV mode with this board. The boards are stuffed and soldered with the exception of the inductors, parallel capacitors and 3 2N5770 transistors which we will include as a kit (specify 2 M or 70cm) with each board for use on 70cm with 10 mW or 2 meters to drive a transverter with 50-100 mW. 70cm crystals (Freq./4) use the same ones as found in all our crytal + multiplier controlled transmitters. We have a limited supply of crystals for 70cm ATV or 1265.0 (1268 MHz Transverter) or 1289.25 MHz (1296 MHz Transverter), or you supply the crystal (order from ICM catalog #473370 - 2 meter F/2 and HC-50 holder) for the frequency you want to end up with after mixed in your Transverter. We made a bunch of these in 1995 for use in our TVX series of export TV transmitters for channels 3 to 13. But not much later Amprex and Philips stopped making the companion 10 watt power modules and no similar power modules are available - that ended that product line. Size is 4x2.25" - will fit in a Hammond 1590C or D die cast aluminum box - and takes 8 to 14Vdc at 40 mA. Use the FMA5-G for sound.
Micro Modules MM434-45 low noise crystal controlled downconverter
I found this downconverter which I used in my cross band ATV repeater back in the late 70's / early 80's. It was connected to the IF input of a 5" TV at the repeater site. Gain I just measured is 28 dB. Input is 434.0 MHz and output is 45.75 MHz IF. You could change the input frequency by getting another crystal. DC power is 13.8 Vdc at 60 mA. It is yours for $30.
Fp/Nj Adaptor...$3 price cut in half
FM ATV Pre-emphasis and De-emphasis Kits
Pre-emphasis in the FM ATV transmitter along with corresponding de-emphasis in the receiver can more than double the distance or add a P unit for the same distance (6 dB) by lowering the noise floor in the receiver. Pre-emphasis and De-emphasis is standard in the USA for 1200 MHz FM ATV systems - CCIR 405-1. However, most board level imported FM ATV transmitters and receivers do not have this feature.
You can easily add on by placing the transmitter PEK kit in the camera video line and receiver DEK kit in the video output line, and readjusting the video gain pots. See our FM ATV application note to see how easy it is. Kits include all parts, solder plated metal can and RCA jacks.
PEK Tx Pre-emphasis kit...$15
GVM-1 Gunnplexer Video Modulator Board....$29
This is a board that has many other uses:
Gunnplexers make a great little microwave (10.4 gHz) ATV link or way to demo ATV and how directional antennas work, bouncing off metal objects, multipath, etc., in a more interesting visual way at ham clubs or ham class rooms.
See the gunnplexer application note - A 10 gHz ATV system is easy to put together. Gunnplexers are available from SHF Microwave and Advanced Receiver Research. Choose those that have varicap tuning diodes in them - the GVM-1 modulator board connects to the varicap to DC bias and FM modulate the Gunn diode in the Gunnplexer.
The boards are $29 if ordered individually, but for ham club or group projects, you can have them for 2-4 $25 ea, 5-9 $20 ea and 10 up $15 each. 25 left.
25 mW in 18W out 68-88 MHz.
Used in our TVX ch3-6 export TV transmitters
includes TC PA bare board.
We suggest RF Parts as a good source for RF Power Modules.
We have an excess of through hole parts that were purchased in large quantities before we started using surface mount parts:
2N5770 RF small signal TO-92 NPN Transistor used in our crystal controlled transmitters and downconverters for the oscillator
MRF901 low noise UHF preamp transistor, Motorola.............$5 ea., 18 in stock.
NE64535 Lower noise NEC UHF preamp transistor.............$7 ea., 25 in stock.
NE25337 dual gate GaAsfet used in our thru hole downconverters.......$8 ea, 20 in stock.
MM3725 Motorola TO-39 NPN used as the video modulator and replaces 2N3734 and 2N3553 in our
MPN3404 TO-92 Silicon Pin Switching Diode, Motorola. Used for T/R switching in our TC-1 Transceiver. $.30 ea. - 152 in stock.
2N2907 TO-92 version of this popular small signal PNP transistor. Used in our sync separator circuits and other products.
MC705K1CP Microprocessor programmed for 88-108 FM transmitter
oscillator driving MC145170 synthesizer IC..$3, all for $1 ea, 94 in stock.
BA1404 Stereo FM Modulator similar to NJR 2035D..$.50, all for $.30ea, 80 in stock.
Ceramic trimmer capacitor, 2-8 pF - Sprague GKU6R000.
Capacitors - disc ceramics, electolytics, etc.
Feed Through capacitor - .001 mF.
Inductor / RF choke, .25 each or $20 per 100
Resistors - leaded 1/4 watt carbon film, bags of 100 or 200 ....$1/100
Potentiometer, panel mount, 100 Ohm carbon - used in our transmitters for video gain control.
Crystals $5 ea: we have a variety of HC-25 plug in crystals used in our downconverters
Power Transformer - 115 / 18Vac @ 3A. Used in our TC-1 ATV Transceivers with a bridge rectifier and
Bias-T Parts Kit............$15
Power your Antenna mounted preamp on the 400, 900 or 1200 MHz band through the coax with this bias T. Great for powering Downeast 23LNAWPQ or 33LNAWPQ antenna mounted preamp from the ham shack. Insertion loss was measured at less than 1 dB. Kit contains LMB cad plated - solderable - metal box with lid, 2 BNC chassis jacks, feedthru cap, 100 Ohm 1/4W resistor,.22 uH inductor and data sheet.
P. C. Electronics, 2522 Paxson Lane, Arcadia CA 91007 USA. Our address is for postal mail only, we do not have a walk in store