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T-MAG ANTENNA 40-10m.
Concept for a small multiband antenna . Can be tuned with most internal tuners.The unun is placed right in the midle of the 13m wire. This isn't a wonder antenna but it can provide good signals at a...
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Magnetic loop controller
There are several ways to control a magn. loop. The simplest direct coax fed method needs a second power source to avoid short circuit. A portable setup is better off with only 1 battery.Here is a no...
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ZS6BKW galvanic feedline isolation
Connecting a balanced antenna like a ZS6BKW to a coax feedline can cause serious problems be means of a high noise levell, for the cabinet of the transceiver is connected to the antenna. This means...
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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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Stubloop antenna
The coaxial stubloop antenna is a 0 gain easy to build antenna for HF - VHF . It's a wideband sulution for emergency use or just as a back-up device. I pubished this article before but received mails...
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FT-817 / FT-857 / FT-897 speaker mod.
The original speaker with paper cone is wel known for his high levell of distortion and noise.A German model train distributor deliveres a 2 Watt speaker with a Mylar cone having the same size as the...
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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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Coax to a pcb
Soldering a coax in to small pcb holes can be verry stessfull. Teflon coax is the best choise.Here is the solution:Free Hit Counters
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Coax to pcb the easy way
Soldering a coax braid in to small pcb holes can be verry stessfull. Teflon coax is the best choise.Here is the solutionFree Hit Counters
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Voice keyer ( CQ parrot )
Calling cq in ssb with ony 5 Watt can cause a sore throat....Although in production for severall yaers this exellent kit BX-184 from Box 73 is stil a must have for the QRP operator. LinkEasy to build...
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Half wave sota antenna idea for 20-17/15/12-10m.
The famous endfed with wireman 450 Ohm can serve as a short 3 band antenna . The short part of the wireman can be calculated for 17-15 or 12m. No coil or trap needed.Free Hit Counters
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IC-7300 preselector idea.
The IC-7300 has a signal overload problem. A preselector can salve this problem.L1 - T80-2 . L2 - T68-6 . L3 - T50-6 .Free Hit Counters
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Antenna switch .
By means of a 230V switch a reliable 100 Watt antenna switch can be made with 2 advantages.1: the switch points to the connected antenna.2: the non connected antenna is grounded.The picture shows the...
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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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