AWA Linc Cundall OT CW Contest (Part 2)

The second half of the AWA Linc Cundall OT CW Contest was this past weekend. Between Saturday evening and Sunday afternoon I added 4 contacts to my log including W0LGU(MN), WA9QNN(WI), WB9WHG(MN) and NG9D(IL). While not a lot of contacts this year my push-pull 6L6 transmitter seemed to work pretty well. I suspect my low antenna (only 10-15ft...

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AWA Linc Cundall OT CW Contest

The first half of the AWA Linc Cundall OT CW Contest ran Wednesday evening through Thursday late afternoon. This coming Saturday is the second half of the "contest".My station this year is a 1938 vintage NC-101X and a homebrew crystal controlled push-pull 6L6 oscillator. Electrically this transmitter is based on the QSL Push-Pull in QST,...

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14W UHF TV RF Amplifier 470-860 MHz

Working Frequency 470-860 Mhz UHF Band IV and V. Power out of the RF Amplifier about 14 Watts with power input 1.5 Watts. ( Transistor Datasheet)SchematicPart Lists:C1 = C6 = C16 = 4,7 pF (500 V) multilayer ceramic chip capacitorC2 = C3 = C20 = C21 = 33 pF multilayer ceramic chip capacitorC4 = C9 = C13 = C19 = 1,2 to 3,5 pF film dielectric...

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RF Amplifier Protector Circuit

This circuit protector is so simple, but it has big function in protecting your rf amplifier device. There are three kind of protect : heat sensor, DC forward - reverse and input over drive. If the input signal more than threshold limit, relay will engaged to disconnect power supply voltage.The input part signals for protecting are :* Termo...

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VHF TV RF Signal From AV Sources.

Small Circuit to send your Audio Video from DVD player or satellite receiver to VHF RF signal. This circuit connected to TV RF input via 75 ohm cable or telescopic antenna. Don’t use this circuit for more power without filter and use antenna only to transmit. Frequency range on vhf band about 50-250 MHz.You can change the transistor for transmitting...

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An Iambic keyer rated for cathode keying

When using my vintage transmitters I've missed not having a keyer. Many older tube transmitters are cathode keyed. The voltage across the key terminals can be high enough to fry the output transistor of a typical modern keyer. In some cases the voltage can even be high enough to be a safety problem.I already had a K1EL K10 keyer board (...

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How To Stack FM Broadcast Antenna

Stacking your broadcast antenna will make your antenna have more gain. If your antenna have more gain, more ERP (Emmittion Radiating Power).What do you need for stacking antenna?- More antennas that identical each others.- Power divider to distribute your RF power to each antenna.- Jumper cables to connect antennasStacking for 4 AntennasAntenna...

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TV Linear Power Amplifier 470-860 MHz

The Wide-Band UHF Power Amplifier for TV Transposer band IV/V designed with transistor BLW32 and BLW33. In this case, my RF Amplifier design replaced them with 2 pieces BLW34 have good result.RF Amplifier for 470-860 MHz taken from Philips Aplication Note (AN_BLW32_33). Please download file in PDF format.For combine two BLW34 download file...

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Low Pass Filter For FM 88-108 MHz

Filter used for eliminate unwanted harmonic frequency at second and third. Notch filter, Band Pass Filter (BPF), and High Pass Filter (HPF) sometime combined in constructing LPF design. Schematic below for FM Broadcast Lowpass Filter 88-108 MHz. It has been tested with a good result.Note : Make the coils at 74 nH and trim them to adjust...

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Antenna For UHF TV Transmitter

DescriptionAntenna used for TV Broadcast Antenna UHF Band IV-V and broadband for 470-860 MHz. . It's called UHF Panel Antenna. The UHF TV Antenna have gain 10 dB. It can be tripled or more the transmitter power. Tne antenna is packed with Radome to protect from ice or snow.Dimension of Antenna and Rad...

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FM Transmitter 88-108 MHz

Main device to transmit signal is transmitter and in broadcast FM is called FM transmitter. FM Transmitter divided by into three block :1. Audio Processing Block2. RF Generator (VCO+PLL) Block3. Amplifier and Filter Block.For covering 88-108 MHz, the transmitter must be wideband FM Transmitter. For stability Frequency output must be PLL FM...

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FM Amplifier 88-108 MHz

FM amplifier is used for amplify signal from exciter in broadcast radio station. In this page, RF FM Amplifier uses solid state material with minimum gain 9dB. Input of the FM Amplifier needs 5-10 watt with power output about 100 watt.The Block schematic and datash...

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Straight Key Night M.O.P.A. Transmitter

After reading a lot of ancient QSTs, ARRL and Jones Handbooks plus e-mail conversations with my friend, Louis VE3AWA about American depression-era style rig design, I decided to build a classic breadboard transmitter in time for Straight Key Night.Well, breadboard MOPA seemed like a very interesting idea, it was absolutely unusual for me...

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