I have other projects like the ARDF 80 Metre Transmitter qrp 4 watt TX
This is the second one I’ve made I need to built a small ATU inside it
I thought a loading coil and a Parrallel 300 pF capacitor to ground so It will tune a 4 metre length of wire
73 Dave

Does the display show anything sensible?

I hadn’t realised before I assembled it that the little row of wires from the LCD to the main board is a tight fit. I was going to put sockets and use ribbon cable but the 1cm long (or thereabouts) row of wires provide quite firm support for the display.

About programming with the unit only partially built – personally I wouldn’t. Get it going as supplied, otherwise if it doesn’t go you don’t know whether the programming didn’t go well or what.

You can find the 28X1 on the View Menu/Options/Mode Tab.

Dave

Regarding displaying your call – should be hard – just another print statement (from memory there’s room for the code).

It’s much easier if you build the programming cable (not difficult – two resistors onto the PCs serial port pin). The resistors are already installed so you only have to add a 3.5mm stereo socket to the analyser and then wire up a 3.5mm stereo plug to a DB9 socket (analyser to PC) cable. Not hard, but be careful to wire it the socket the same way as described in the Revolution Education PicAxe manual. The way they’re arranged the pins seems unnatural (ground isn’t the sleeve of the 3.5mm plug) but it what get’s connected to what was you plug it in doesn’t do any damage (anyway that’s my take on way the plug wiring is “odd”).

There’s a very clear diagram of how to wire the programming cable on page 31 of the PicAxe manual at http://www.rev-ed.co.uk/docs/picaxe_manual1.pdf

I was fairly paranoid about checking the connections from the DB9 to the socket and then to the PicAxe as while the Analyser PC board has the programming resistors installed and three pins for a cable, the actual connections aren’t detailed in the documentation.

Just be careful – the flexibility to be able to reprogram the analyser by just plugging in a programming cable is well worth an hour of paranoid checking. Then you can try all three versions of the software in a few minutes without even opening the analyser …

Cheers
Giovanni – ZL2BOI

The symptoms of the PN2222 being in the wrong way around was really low output from the amplifier and a really fast drop off in output with frequency. The documentation states that the -3db point of the power amp is 70MHz so there shouldn’t be a roll-off happening at 14MHz which mine had.

Cheers Giovanni

I use one of these antennas. It proved to be much better than a normal G5RV. I have also tried a 60m dia loop and various verticals, but the measured performance of the ZS6BKW was either better or in the worst case equal to the other antennas. Too many antenna recomendations are not based on fact, so don’t believe everything you read. G5RV’s seem to have a bad reputation, so you’ll get better signal reports if you say you are using a open wire fed doublet !

The key things to watch when constructing the antenna are:-

get the length of 450 ohm open feeder correct. The velocity factor of the stuff I used was not as advertised. I measured it with an antenna analyser and cut it to the correct length.
Use a good 1:1 balun at the end of the 450 ohm feeder. This drastically reduces the receive noise level on 160m and 80m. Note that a few turns of coax do not make an effective balun. You need plenty of ferrite.

See http://www.geocities.com/martin_ehrenfried/HFantennas.pdf

I’m now working on a remote switching box to strap the feeders together for transmit on 160m. Tests proved that this gave a 20dB improvement over the antenna running in it’s balanced configuration on this band.

Regards,

Martin

I built one for 20 meters and put it in a Hammond 1590N1 die cast box. It’s a little cramped, but everything seems to fit. I’m already modifying mine by replacing the 1 Meg resistor at the audio chip with a 1 Meg pot for volume control, replaced the 100 ohm resistor R8 for a 1K pot to dial the side tone to my liking, and installed a small 500 ohm pot in a voltage divider configuration to ground between L2 and the transformer to give me some gain control. All controls fit on the ends of the box. I didn’t bother with a power switch. No room is left for it anyway. I figure just pulling the power plug out of the jack should be sufficient.