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He's a nutter ! It's wonderful to see his work.

I did. The design was an on going project over many years. It started with just a crystal locked radio, but then it grew, and grew out of control. Orginally it was AM, then I put in FM. SSB was too hard for a long time. I had a DBM + BFO for DSB suppressed carrier, then I learned how to build...

You guys should visit your local Congressman and stir them up. Tell them you want GRMS expanded, and the licences reduced $5 a year or licence free like Australian 477MHz UHF CB. While you're at it... push the ARRL and congress for a new class of ham radio licence. There is a new class of...

As an RF worker my employer makes a little bit of effort to make us aware of non-ionising radiation. Basicaly the amount of transmitted power is where you start. Low powers aren't an issue, but high powers can cause burns which can have a bit more of a perminant effect. Second is the...

The coax is 50 ohms. The -50 designator gives it away. This stuff sounds VERY similar to Andrew Heliax LDF1-50 coax. RFS also make a very similar coax RFS12-50 You guess it 12 means 1/2 inch and -50 is 50 ohms. You can find the specs for these cables on their manufacture's websites...

Yes, the torriod transformers in that circuit are wilkinson dividers. The kind I would normally build at SHF frequencies, though they don't use ferrite, they're just stripline. The dividers aren't the problem. It's the combiner. You'll notice that if you just treat each push pull circuit as...

Buck and Boost normally refer to the operation of a switchmode power supply. Though it may also be something else, but I will stick with what I know, the operation of switchmodes. Lets start with BOOST since it is the easiest to understand. You may have played with a large coil and a car...

This has got to be the world's simplest geiger counter. http://home-and-garden.webshots.com/photo/2033951890048941318ufVtyb 3 volt battery, 1 transistor, 1 transformer, a couple of diodes, capacitors and resistors, a GM tube and a high impedance or piezo electric speaker.

The power modules themselves really aren't of any concern, they could be mitsubishi modules or transistors etc. In my case they are 50 watt 1.3GHz SSPA's, so the power is high to start with. I want to combine them 4,6 or 8 fo an output of up to 400 watts minus losses. The problem I have...

Homebrewing from scratch I would agree is not the forte' of the CBer. It might be correct, that CBers would more actively modify their equipment than Hams. The complexity and expense of ham equipment means you have more to learn about and more to lose than breaking a CB. I cut my teeth on CB...

If you really want to compare cables / transmission lines, the you have to really look at two things. Insertion Loss - Which is how much power you get out at the other end compared to how much power you put in, over a fixed distance. (usualy 100ft or 100m) Return Loss - Is how much power...

The difference in return loss is due to standing waves in the coax. There readings that you get may not always be correct. You should own a dummy load, connect that to the end of the coax under test and repeater the readings at several frequencies. The worst reading will be the most correct...

We have a very good tutorial on our ATV club web page too that deals with testing transmission lines. Everything you might ever want to know from the basics up. There is even a section on why you notice a difference with your SWR meter when you cut the cable to different lengths...

I'm looking at ways of combining several amp modules to make a single high power amp. I've been consideing a few different methods each on it's own merits. Normaly at lower powers, it would not be an issue. But at high powers, small mistakes can create big fires :) I'm wondering if anybody...

Our local police are all digital now. Motorola Sabre systems. I'm keen to try Dstar to see how it performs. I'll have to save my pennies. Buying one is going to hurt, I'll probably have two buy two to test them out. It's going to hurt even more so that I just purchased an IC208. For a few...

Good post. Here's another FAQ on AM some of you might like to read. http://www.funbusters.net/am.html http://www.satvg.org/smf/index.php?topic=6.0

SUPERSTAR 7000DX Wish I'd never sold it, but the Yaesu FT767 does the same job now :-)

thanks roger, that's got it.

I use a dual gate 3SK121 for 2m. (SSB) a dual gate BF904 for 70cm (ATV) a single gate MGF1302 for 13/23cm (ATV) I don't know what your motives are, usually EME is the reason for running low noise pre-amps. But ATV they are important too.

But just because I am modifying the radio to do something that would be considered illegal in your part of the world, doesn't mean to say that it is in my part or that I intend to do anything illegal with it. My mere possesion of the radio in question might be illegal in some cases. If you...