Ham Radio Kits
Ham Radio Kits
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Solarcon I-MAX 2000 CB/Ham Radio Base Station Vertical Antenna - 24' $99.18 Solarcon IMAX-2000 24ft Omni-Directional Fiberglass Base Station Antenna 5000 Watts.... |
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Pyramid PS3KX 3-Amp 12-Volt Power Supply $33.00 Amp power supply, perfect for home, shop and hobbyist.... |
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60 (1.5m) WiFi Pigtail N-type Male to RP-TNC $19.95 Ultra Low Loss Cable is designed to transmit the maximum signal to your antennas. LMR-240 cable by Times Microwave USA meets Military Specifications with silver foil and silver coated copper conductors for less signal loss in runs up to 200 feet.. In this high quality cable, the dimensions and spacing of the conductors are uniform. Any abrupt change in the spacing of the two conductors along the c... |
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30A Power Pole Connector (4 Black, 4 Red) Anderson-Sermos $8.95 PowerPole connectors (formerly known as Sermos connectors) from Anderson Power Products have been very popular with electric airplanes and sailplanes. They were the first low-resistance connectors - made of silver-plated copper. The secret of their success is the stainless steel leaf spring built into the plastic housing. This spring applies 25 lb of pressure onto the contacts, ensuring good, vibr... |
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BLMA Models HO Scale Kit Radio Tower w/Antennas $35.99 HO KIT Radio Tower w/AntennasBlma ModelsPart BLM4101... |
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Marine Grade Cigarette Lighter Socket 12 VDC $4.99 This 12 volt receptacle is manufactured from corrosion resistant marine grade materials. It features an interconnecting system that securely locks the plugs into the locking receptacle resulting in a positive and moisture proof connection.... |
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Midland 75-822 40 Channel CB-Way Radio $74.99 Having a CB radio while traveling can be an invaluable tool for emergencies and for keeping up on road conditions, and the Midland 75-820 40-channel handheld CB is one you should definitely consider. It comes with everything you need to get started in a hurry, including a battery pack for times you want to run the unit on six AA batteries and a cigarette lighter adapter for battery-free operation ... |
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Handheld VHF & 2 Meter Amateur Radio Tranceiver 5watt, TYT TH-F5 Ham Radio $78.50 VHF & 2 meter Handheld 5W transceiver, 136-174Mhz . Direct Keypad Freq & function entry. 128 AlphaNumeric memory channels, Scan modes, PL & DPL (ctcss/dcs), selectable step rates & repeater shift. Has regular Amateur SMA antenna jack, & a "Kenwood Style" 2-pin speakermike jack, for compatibility w/ many aftermarket accessories. Optional PC programming cable available.. 5W / 2W / 1W Output setti... |
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Crystal Radio! 21 Books About Wireless And Crystal Radios $3.50 Crystal radio!21 historical books on CD containing valuable knowledge about wireless and crystal radios.History, techniques, methods, design and more and more!!Titles:Elements of radio telephony, by William Cyrus Ballard, 1922, 158 pagesManual of wireless telegraphy and telephony, by Archie Frederick Collins, 1913, 319 pagesPopular radio, by Raymond Francis Yates, 1922, 677 pagesPractical radio, b... |
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Build Your Own Intelligent Amateur Radio Transceiver $25.49 With the help of this sure-fire instruction guide, you can learn how to build a sophisticated, yet low-cost microprocessor-controlled radio transceiver as well as smaller devices such as a simple frequency synthesizer and a spectrum analyzer. Filled with tested, hands-on projects that really work, this great reference features single-sided circuit boards that are easy to build, and includes detail... |
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Build Your Own Low-Power Transmitters: Projects for the Electronics Experimenter $42.05 Rudolf Graf and William Sheets have written a book containing twenty low-power (LP) transmitter projects, perfect for the electronics hobbyist and radio experimenter. Now that the FCC has changed its regulations about "pirate" transmissions, more and more people are setting up radio and video stations for broadcast from their homes. Build Your Own Low-Power Transmitters addresses applications for ... |
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Midland XT511 22-Channel FRS/GMRS Two-Way Emergency Crank Radio $89.99 Midland's XT511 is a durable GMRS emergency crank radio with a wealth of features to keep you informed, charged up, and in contact no matter the situation around you. Stay in touch no matter your environment. Dynamo crank allows recharging of batteries without access to electricity. Built-in flashlight and USB port for charging your cell phone or other device... |
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Midland 1001Z 40-Channel CB Radio $31.83 Keep in touch with your buds, be prepared for emergencies. Compact Midland 40-channel CB Radio, SAVE BIG! The time honored way to keep yourself entertained and up-to-date on changing road and weather conditions. Independent RF gain control and squelch for crystal reception. Pro-quality microphone and PA connector for loud-and-clear transmission. And the easy-to-read digital display means you'll ne... |
how to convert a 40meter ham radio receiver into a 80 meter receiver?
how to convert a 40meter ham radio receiver into a 80 meter receiver,
I have a kit to make a 40 meter ham radio receiver, they 80 meter receiver has been discontinued, I hope there is someone who could give me a little bit help.
the kit is a 40 meter direct conversion receiver it uses a sa602 chip, two varactor diodes and two toroid ferrite coils that are hand wound.
Dear Jimjuta,
Direct conversion receiver is oldest type of receiver that designed before superheterodyne receiver system. In direct conversion, joined carrier signal and AF signal directly extracted/filted to get AF signal. While in superheterodyne system, joined carrier and AF signals, first developed to get IF (Intermediate Frequency) signal. This IF signal then amplified in order receiver to be more sensitive, then as final result: AF (Audio Frequency).
Superheterodyne developed because IF amplifier which frequency is much more low than RF, is easier to designed.
If you like to change frequency of your receiver, you should be able to modify oscillator/local oscillator of your receiver. Oscillator developed from many models: with LC tank, VCO, Crystal, etc..
Eg. oscillator with LC tank: main formula for resonance frequency: Fr=1/(2π√(LC)) . If values of L and C increased, resonance frequency would be lower. Of course if you modify oscillator, you would need oscilloscope which maximum frequency measurement is approximately 5MHz (because 80m band is between 3.5-3.9MHz).
In order to modify, you should understand internal circuit of SA602, so please download this link (just click): http://go2.wordpress.com/?id=725X1342&site=frrl.wordpress.com&url=http%3A%2F%2Ffrrl.files.wordpress.com%2F2008%2F11%2Fne602.pdf although this is datasheet for SA602A. On that datasheet, figure 7 shows various tuning circuits attached to pin 6 and 7, and figure 8 shows circuit if you are using VCO with synthesizer. I do not know what circuit you are using. SA602A could produce oscillation up to 200MHz, so modify it to 3.5-3.9MHz, I hope is alright.
I could recommend You good book to design oscillator: "Transistor Circuit Design With Experiment" by Delton T. Horn, and another good book to design coil/L/inductor: "ARRL Handbook".
Have a nice experiment.
Thank You very much Jimjuta.