The design is somehow up-side-down, it is because the power fets are mounted on the heat-sink which is on the top of the box

JUMA TX136 is a digitally controlled CW transmitter for 136 kHz 2200 meter amateur radio band. The transmitter is available as a component kit which inludes all the electrical and mechanical componets

The vertical is based on my old Butternut HF2V 40/80m vertical,this forms the vertical section of the antenna, and is free standing at 10m high

Canadian amateurs have full access to the 2200m and the to 630m bands without the need for special operating permission

Antenna configuration for 136 kHz,it's consists of a 10m fiber pole which is coming out of the window of the attic with 2 * 15m toploads made of 0.32 mm insulated copper wire

Design 136 khz antenna

For use on 136khz transverts to and from the 10mhz amateur band, this band was chosen primarily because 10mhz computer crystals are cheap and readily available

27 MHz xtal oscillator, x200 divider, 180 W power amplifier with 1 x 2SK1029 mosfet under construction 400 W power amplifier

During our stay in LX later this year I want to take some equipment for 136kHz with me

This is the TX freq logic, using a 27Mhz CB xtal and dividers to generate the 136 Khz The 27.407 Mhz is divides by 2 and then later by 10 in two 7493 counters then the 1.37035Mhz is feed into a 4017 decade counter, this one divide the freq by 10 again,Now the output freq is 137.035 Khz, the smart thing about the 4017 is that I can use the 10 outputs to generate the two outputs to my push-pull stage epending on how meny outputs used the pulse width can also be controlled

Hiperfet power mosfet ixfn55n50 500 volts at 55 amps, currently running 28volts at 14 amps input, output 265 watts

It's radiator consists of a #14 THHN vertical wire 95' tall

I have re-erected the mast at the house end and reinstalled my inverted-L Marconi, so am back on the air again

First transmission experiments on 136 kHz band where based on a little TX build around surplus component

The grey metal box at the bottom of the loop houses the tuning capacitor bank and the ferrite core matching transformer

Due to the increase of sunpanels and plc devices, the hf radio spectrum is more and more polluted. add to it that in nl there is certain group of sunpanel pioneers who consider themselves capable of installing these devices by themselves

The transformer in the picture is an FT-50-77 core with two turns on the primary and 20 turns on the secondary

Transmitting station 2ele delta-loop for 160m t-type for 2200m 50m high

This circuit for 630m, uses 2 mosfets in push pull driven by square-waves from a cmos d-type flip flop, the power can be varied from around 25 to 300w

The amplifier described, uses four low cost Power Fets to generate 250 Watts output on the European 136 kHz L.F

The description of an easy to reproduce transmitter for lf that can be used as a mept - manned experimental propagation transmitter

Just about anything i plan to use as an antenna will require a serious loading coil, i decided to construct an experimental

E' possibile costruire un'antenna in ferrite per LF ottenendo buone prestazioni con una spesa assolutamente irrisoria

The qso made in cross mode at the same qrg because my set-up has not the capability to tx audio, but only cw qrss and opera

Calculations indicated that there was close to 35,000 volts present on the antenna during high power operation

The loop atu consists of a capacitive matching network 3 capacitors and a toroidal 4:1 balun, the balun is made using 18 bifilar-wound turns on a 58 mm

Antenna for 136kHz as this often is the most important part of a longwave amateur radio station, the aim of the transmitting antenna is to radiate the power coming from the transmitter

If stands for low frequency, that portion of the rf spectrum extending from 30 through 300 khz, in europe, where there are numerous broadcast transmitters between 150 and 250 khz

I have been using power-mosfets to produce several hundred Watts for some years now so it seemed a good idea to employ them on 136kHz

Un finale di potenza per onde lunghe a mosfet che ho provato a realizzare

>What I am using for LF antenna matching is a relatively small ferrite pot-core instead of big coupled air coils

Getting on the air with a LowFER station is more complicated than getting on the ham bands since commercial equipment isn't available and construction is involved

Tower antenna without top-cap, a total length of 24 meter

Vertical design progress was rather slow because of other commitments, but by the autumn it was complete and i was able to have some qso

Experimental lf station wd2xns -experimental mf station we2xgr/2 - burlington ct us

The present transmitter is a zl1bpu dds exciter driving a g0mrf 300 watt amplifier

The power radiated by an antenna is equal to the radiation resistance multiplied by the antenna current squared, measurement of antenna current can be done in the 137 kHz band by for instance a thermocouple ammeter or other means

Vertical antenna built with, about 22 meter high vertical pipe, with 4 top cap wires at a total length of 18 meter

I've recently changed my LF driver from one which covers the band in 100 Hz steps

I have re-erected the mast at the house end and reinstalled my inverted-L Marconi, so am back on the air again

For 137 kHz the coil has about 200 turns of enameled wire

With UK amateurs having had access to 136kHz for several years, a lot of experience has been gained matching transmitters to a variety of LF antennas

When adjusting the tuning and matching components of an LF antenna, it is extremely useful, if not essential, to havesome way of indicating the impedance mismatch at the antenna feed point

Transmitter 400w from 2xirfp250 with lf dds vfo, receiver icom ic-761 with 2x500hz and 2x250hz cw filters, tx antenna 135m long wire

LF-Station DF6NM

Old Longwave equipment for 136kHz

Primary 3.4 mH loading coild 1/3 way up the antenna,this coil improved my ERP signal about 4-5 dB

The 136kHz signal is filtered by a very narrow 2-stage FET preselector using Q-multiplication feedback to increase the Q factor, its bandwidth is less than 200Hz

The antenna requires 4mH at 137 kHz to tune it and I have built a loading coil with a variometer using two polystyrene plastic

The antenna requires 4mH at 137 kHz to tune it and I have built a loading coil with a variometer using two polystyrene plastic

The old long wave antenna in kraak, near karlsborg, on the 136 khz amateur radio band, we received a special permission from pts to use 1 kw emrp

There is no preamp at the loop! In the shack, the RG-58 connects to a 50 ohm in/out preamp

Un tx ibrido transistors - valvole da 50w.out, ed un antenna verticale di fortuna si sono raggiunti i 10 km. in cw standard

Argo is a viewer for slow CW, like QRSS and DFCW

Antenna ombrello per 136/475 khz

Low power cw transmitter for long wave

he PC is used to convert the VLF signal into a souncard runs at 44100 Hz nominal sample rat

La realizzazione è stata anche abbastanza celere e potrebbe essere un'antenna per portatile o per qualche altro evento

The main equipment for 136kHz is a linear transverter with a maximum output of 100 watts

A variometer consists usually of two coaxial coils, connected in series, where the coils relative position can be varied in some way

The passion for radio listening on HF and lower band, down to VLF

136kHz antenna by placing a part of the loading coil at the top of the vertical part

Very low frequency or vlf is the itu for radio frequencies rf in the range of 3–30 khz, corresponding to wavelengths from 100 to 10 km, respectively

Un circuitino che ho a lungo utilizzato per l'ascolto delle onde lunghe

Ith two crossed loops, one north/south, one east/west, radio-direction finding on vlf is possible

The schematic above is a simple up converter which i used in conjunction with a short-wave receiver to quite successfully to monitor solar flare activity a few years ago

Low power cw transmitter for long wave