Slowly integrating all these bits together in software and currently all the relays are clicking in sequence when I change bands on the control board. If you look closely on the upper right, you will see an updated version of the Band Pass Filter board that uses different inductors and filter topology. I need to populate and test one filter to ensure its right and then build the entire board.
Something that I did not notice was that when I changed Ecad software my mounting hole pattern has changed slightly, so neither of the old filter board designs will stack with the other boards. So i have to redo the low pass filter board and I am going to redo the rf frond end board as well and move things around to make it a little more usable and to make sure the 3.3v regulator has a heatsink on it. With bugger all current running though it, it still gets burn your finger hot and that is not right. I am starting to wonder if these ebay parts are actually dodgy or something.
Its taken me 4 and 1/2 years to qualify for Worked All Prefixes. Mostly this has been achieved using low power. I wouldn’t even call it mostly QRP. Maybe 50% at most. However its all been done with low power. And by low power, im talking less than 50 watts.
For 4 years i was license restricted to 10w SSB and CW and made over 1/2 the contacts. But since upgrading and getting FT8 and other digital modes, mostly I have been running between 20 and 30w.
FT8 has been a game changer for me. I have really upped the contact rate. Like close to 1000 contacts in 6 months and that is not being very active on the bands.
So along with the main WPX award, I qualify for 3 endorsements. WPX Digital Asia, well given that I have been operating almost exclusively on FT8 that one is no surprise. The other 2 are also low hanging fruit , Asia and Oceania. If you cant work everyone in your region there is really something wrong no? LOL.
The only disappointment here is that LOTW wants $50 Usd to process the award. Add in the 3 endorsements and cost will be $100 Usd. Converting to local currency that is $150. That is an extraordinary amount of money to have an award processed. Obviously I am not going to pay that. You would have to be mental in the head to spend that kind of money to have someone rubber stamp your participation award, so that the award manager can rubber stamp your award.
Applying for the award is $12 + postage Usd. Not bad, and reasonable. But, if i wanted the endorsements then that is 4 time $12 + postage. Say about $100 Australian. So in total, I could spend $250 or 1/4 the average weekly wage to get a participation certificate and 3 add on stickers
And they say ham radio is not a rich white mans folly. I mean, come on, that is an extraordinary amount of money for a piece of paper that only has some meaning to me that I have passed some arbitrary number of contacts. Horses arse comes to mind for wasting that much money on a piece of paper.
In a follow up to this, you actually do not have to apply for the award and get extorted by LOTW. You can fill out a spreadsheet and apply directly to CQ Mag and bypass the middle man. Now they might ask you to confirm some certain contacts just to be sure to be sure, but then you are only paying LOTW for a couple of confirmations and thats gotta be better than spending a small fortune on nothing.
So I will probably fill out the spreadsheet and apply for the main award. Being a paper chaser that i am. HEHE
I did a bit more on this today, went through and added in the first IF amp and tested it to ensure it was working. After sorting out some probe issues with my scope, it was all systems go.
After working out where the input to the first IF amp was and also buzzing it out back to the first mixer, I fed a 100mv signal into the amp and scoped the output on the other end of the xtal filter to ensure signal was going in and coming out. As you can see from the oscilloscope output above it works.
The blue trace is the 100mv signal from function generator and the yellow trace is the signal on the other side of the xtal filter. Now to build the 2nd IF amp and test it also.
So the RF preamp has about 5x gain. On 40m its probably not really needed unless there is a lot of loss in the filters. Which in this case might actually be the case as the RF path from the antenna goes through the LPF, into the Relay and then into the BPF. So a little gain ahead of the mixer might be a good thing.
One thing that I left out for now were the back to back clipping diodes. I am only building this as a receiver pretty much to begin with and I am not sure clipping diodes are really necessary. Next I will be working on the LPF and BPF. Need to do some LTSpice here to make sure my values are correct.
Ok, back to doing some work on the Bebek. In this block the only real issues are that there is an extra DC blocking cap on the board that is now shown on the schematic and that the Cap values on the schematic are not the same shown on the board. In this case I have defaulted to using the values on the board. 10nf and 100nf on the board are 1nf and 10nf on the schematic. The former values just seem more logical to use and the latter are most obviously an error on the part of the designer.
So the LO Buffer Amp has a 10x gain. I injected it with a 250mV signal to get 2.5V out. Now obviously this is not good if you are using a SI5351A as it puts out 1.5V. But this should work quite well with an AD9850 which puts out 200mV. It still might be a little to much drive for a -7dB mixer, but it should be ball park upper limit.
I have seen HC2AO pop up a few times on 20m over the last couple of weeks. Have put out calls, but he could not hear me. So today when he again came up on FT8, I put out a couple of calls, got on PSK reporter to see that I was being heard, then persisted calling. A couple of QSO’s later and I was in the log. Thats another new one in the log and another new one confirmed. Not bad for 30w and a 1/4w vertical.