Monthly Archives: March 2013

G1 and G2 boards

I got a few boards today that SA5BJM wanted me to design and since I needed them for my own project I did. The G1 board is based on a DC9DZ design which I modified some values to suit the QBL amplifier. I haven’t tested it, I am missing a 230->110v transformer that currently is at SM3WMU QTH since he transported it from SA5BJM when he was south last weekend.

I also tried the anode choke. First I had 4 sections (no real need to wind sections for this since I have a ferrite, but I did anyway) and got 800uH indutance so I changed to 3 sections and got about 550uH. I did some quick measurement and seems like I have no resonances below 30 MHz which was the goal.

Tomorrow I am heading down to SJ2W and I will be QRV SOSB 20m this weekend.

QBL amplifier

Today I got more work done on the chassis for the QBL amplifier. I had forgotten my phone at home yesterday so I could not take any pictures, but I did take some today instead. I got the HV rectifier assembled, made an anode choke out of teflon and 61-material ferrite rod. The idea is to get a lot of inductance without needing to get any resonances under 30 MHz.

I also got the L-iron welded together and now it’s ready for the aluminum side plates.

QBL chassis

I have been working on building the chassis for the QBL amplifier. I tried to find some 19″ rack unit but unfortunately I could not get hold of anyone big enough, so I decided to build one myself out of 20x20x3mm L-iron. After cutting them with my new RAGE 2 saw I used a drill press to thread 120 pcs of holes for the aluminum sides, which I will need to cut later. I need to borrow some equipment to cut those so that they look good.

I built the box quite large, but I rather have it too big than too small.

I have also milled a few boards that will be used for the amplifier project, one is a rectifier board and the other is a couple of zener diode boards.

Inband progress

It has been slow with updates lately. I have been spending some time designing electronics for my new amplifier project with a QBL 5/3500 which was donated by SM3BDZ. The tube isn’t in perfect shape (90%) but it’s good enough to start building on. I will start posting pictures as soon as I start building something for it. Currently I am waiting for the RAGE 2 saw that I ordered from England to help me cut the L-iron needed to build the chassies for the amplifier.

Meanwhile today when I was milling boards for work I did some work on the inband electronics, the never ending project which I am very tired of working on. But now today I got most of the hardware done. Now I will need to finish the programming and also make some cases for the manouver boxes. Hopefully it will be ready for the first real try in WPX CW, since the broken coax to the vertical 500m from the QTH should be possible to fix by then since most of the snow should be gone.

I have talked with the neighbour about getting to put up a tower on his land and he said it was no problem. I guess we will need to write some kind of paper on it later and my plan for this is to run 400-500m of hardline over there and put up a 18-24m tower with some beams on 10-40m and some kind of antenna for 80m as well. That way we should not have more than maximum 3dB loss and we could use that for the inband instead of needing to share the main antenna system. This will however probably not be done this summer, but it’s a future plan. SM2RIX got hold of a drum of 1 1/4″ hardline (220m long) for us, that is a good start for that. Hopefully somebody else will donate or sell cheap the rest that we need.

I also spent a bit time last week at the local radio club here at the work QTH talking a bit about SJ2W. It was fun, more than expected amount of people showed up and I got to know a few more people, which is always fun.

Here are some pictures,