This one has been a long time coming. Its alot harder for us in vk4 to work the southern stations in VK3 and VK5 where most of the action is, so getting here with only 10w and a crappy dipole is a pretty good effort.
Today i pulled down the old antenna and mast and put up a new and improved version of each. The old shortened 40m dipole was only ever meant to be a temporary solution that stayed in place for 3 years. So it was time to bring her down and put it to rest.
I bought a flag pole cause it seemed like a quick and simple way of putting up a new dipole and a balun because i want to be one of those balun guys who has to tell you what kind of balun he is using even though its kind of not important to the conversation but the word balun gives the air of technical know how and ability especially when you say its a 9 to 1 balun which is really an unun or as I call them 9:1 onions, because endfails will make you cry, but I digress. <– this is called sarcasm to anyone who is going to get hurt feelings over their antenna of choice, don’t email me call your local politician and complain to them.
Erected the flagpole and hoisted up the balun and new dipole cut for 40m on the flag raising rope, saluting while humming the national anthem and got the ends up in a temporary fashion to check the long or short of it with the analyzer, when the wife gets home from work. She comes out the back, looks at the new flag pole and remarks, Oh great, its storm season and you go and erect a dirty great big lightning attracter. Chuckles to herself and leaves me to antennaring like i know what i am doing. And if my Pythagoras is correct, when i put the ends up about 4m in the air, i should have 50mm to spare. The joy of living on a postage stamp block in the city.
I guess it has happened to just about everyone. You drive for an hour, get to your destination and go to set-up the radio gear and notice you have left the antenna at home. LOL well it happened to me yesterday. Its the first time i have forgotten anything before.
So rather than waste all the effort, we popped over to Bribie Island and went to the beach. Its not radio, but have look at the weather. Nice huh.
I have been slowly clearing things off my bench either to the its complete pile or the it does not work look at it another day pile. And not that that is done, it is time to start on a major project that will take sometime to complete. I really wish I had the time to knock out rig a week like Pete Juliano, but alas I am neither that skilled or that time free LOL. Anyway, so what am i going to build, well a receiver to start with that might eventually morph into a transceiver.
Starting initially as a direct conversion and later becoming a single conversion superhet, It will loosely follow the simple-ceiver, simple-ceiver plus builds by Pete, which can be read about on his blog HERE: and a few bits off the bitx hacks page which can be found HERE:
Mixers will be Mini Circuits ADE-1, oscillators will be SI5351a with an Arduino powering it, audio will have AGC and some kind of audio filtering for both CW and SSB, I am currently not sure if i will go passive or use a Teensyduino and DSP audio filtering, I have the bits for both so either or can be done quite easily, but filtering will not be part of the initial audio amp build, all the rf amps will be Pete’s J310 as dual gate mosfet amps, bandpass filters will probably be my own 3 band switched module.
So that is the rough details of what I am planning to do, now its a matter of starting to build it. With that in mind, I will be starting tonight on the audio amp stage, using the AGC from bitx hacks for the bitx 40, a 2n3904 preamp by Pete Juliano and a TDA2822m in bridge mode. I will be building each stage on its own scrap of board for testing in isolation using manhattan construction and Me Squares.
A friend of mine, Simon, VK6MSC has set up a Kiwi SDR radio that is running 24/7. Apart from his qth having a very high noise floor, the radio itself seems to work quite well and is a good tool if you want to check propagation to VK6, which is a land far far away.
So i got busy today and wired up the uBitx. Turned it on and tuned around a little to find some signals, well there was not much going on anywhere but I did manage to find this one ZL on an other wise dead band. Its good to know that the receiver works, now i just have to wire up a mic and check its working on transmit. But that is going to be another day.
So I recorded a little video from tonight’s 7.130 dx net. I have been giving the receiver a good workout to see how I like it. So far, to be honest, I think i prefer the Bitx40 over the uBitx. Though, it might be I just need to play with the IF and BFO settings to move the bandpass around a little to where I think it sounds better.
Started to put the uBitx into a case. I did the front panel up on a mini cnc and it certainly has turned out better than anything i have hand cut in the past. Used 1mm aluminium plate with is nice and easy to work with and the filing to clean it up at the end did not take long at all. Its not perfect, there are a few things that could have been aligned better, but it is what it is and that’s how its going to stay LOL.
Something i was not happy with was how the heatsinks were mounted flush to the board. If you use this radio portable eventually they will rub through the soldermask and short out on traces. So i grabbed a couple of other heatsinks i had laying about here, drilled and tapped for some isolation between heatsink and board. I also using insulating hardware as well because the fets tab is live and things go bad when you short things to ground that are not meant to be LOL.
Board is now mounted and just awaiting wiring up.
Front panel now with knobs on. Just have to wire it up and be done. Oh and yeah I use a speaker not headphones so I can use 1 less jack and I also use a 4 pin mic socket rather than jacks.