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Max.loop size for 20m. and projects
15MM COPPER TUBING LOOPMagnetic loopantenna calculator by KI6GD : http://www.standpipe.com/w2bri/software/loopcalc.exeThe prog. doesn't have an icon, just klick in the white square above it's name .DO...
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20m. end fed halfwave antenna
Working portable demands an easy setup of your antenna. The antenna also has to give enough punch at a low radiation angle without the need of radials.The vertical end fed half wave antenna is my...
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Travel loop antenna type 40-10 and 80-10
Haunted as many others by radio interference and noise I started looking for a wideband portable antenna . Soon I became focused on a magnetic loop antenna. The only catch was the method of feeding...
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Z-Match 100 and mini Z-Match
FIRST TEST WITH A 4C65 TOROIDThis is a one for all antenna tuner with wide range tuning on all the HF bands. The tuner is based on a G3WQW design. A T200-6 should give a better Q but the T200-2 was...
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No ground antenna for backpackers, balconies or plastic car bodies
A common problem with backpacker or balcony antennas is finding a good counterpoise. Also cars and caravans with a plasic body are a problem. Althow nothing beats a set of resonant radials, the shown...
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Multiband end fed antennas 3.5 - 30mHz
This is a 200 Watt PEP step up transformer for end fed full and half wave antennas without radials, designed as a 200 Watt PEP upgrade by PA0EJH for the originaly Par Electronics designed 25 Watt HF...
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Adjustable bandwidth
A MAX7400 is an 8th order elliptical filter giving a 100 Hz to aprox. 3000 Hz tuning rate. It means much more selectivity in many homebrew receivers.The output can drive a LM386 . This filter is a...
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ILER 20 QRP MODS
My Iler 20 is finally oparational. The IF has changed to 4.000 MHz and the vxo has 10.250 MHz cristals.(Ebay) The VXO coil now holds 64 turns no.26 (0.31mm) magnet wire and the tuning range with the...
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End fed half wave high pass for 20m.
A common problem with qrp transceivers is a weak frontend . Most end fed antennas use low pass tuners causing high stress due to strong signals coming from BC stations .The High pas tuner used here...
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Broad band 1:1 current/choke balun
In search of a no nonsence 1:1 balun i came up with this easy to build unit. It offeres a almost flat swr curve from 1 to 30 MHz as you can see in the plot. Use 10 turns of side by side1 mm enamelled...
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Mini Travelloop for receivers
Portable shortwave receivers are normally equiped with short telescopic whip antennas producing a poor reception. This option has more selectivity and a better impedance (low Z) over the 5-21 MHz...
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Single knop Travelloop 6.5 - 31 MHz
First attempt with a large space between the loopsThis small loop can handle 20 Watts from 45-10m . Loop circumference is 2.5 m with a Faraday coupling loop of 50 cm . Sticks are 6 mm glass fibre (...
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1:4 Voltage balun 3.5 - 30 MHz
Flat SWR from 3.5 to 30 MHz with 8 double turns on a 4C65 or FT140-61 toroid.SWR 1: 1.1 in the centre. Free Hit Counters
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Wall Loop 20m.
This max. size magnetic loop antenna for 14 MHz with a totall circumference of 6m. ( 19.68 feet ) is designed to attach to a wall . Not sutable for reenforced concrete walls . It has a no tune...
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DIY kits 70W SSB linear HF Power Amplifier For YAESU FT-817 KX3
It's time for a new project. eBay link to the seller OM's in need of a doc. copy please send me a mail , i'm happy to help. E-mail adress at QRZ.comIt seems that the seller often...
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EFHW antenna for 40-10m qrp
A small QRP EFHW transformer is possible using a BN43-2402 balun core from 7 - 29 MHz. As you can see in the plot the swr is verry flat from 40-10m so a capacitor at the input is not needed. A 3300...
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QRP labs QCX 5 Watt cw trx kit
Here is my new winter project: http://qrp-labs.com/qcx.htmlI couldn't resist buying this little 10 x 8 cm gem with a lot of features for just 49$The two SMD ICs are already factory pre-soldered.A nice...
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Yaesu VX-3 double battery idea
A small radio has a small battery so i came up with this idea. A battery case for AA size batteries is available on the net . By removing all inside material with a Dremel tool enough space is created...
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