Change of Pace

It was time for a change to clear the head.  Having all kinds of trouble troubleshooting the LBS project. Measurements that don't make sense, circuits that did work appear not to  now or don't work all that well. Doubt in measurement techniques even the simplest part of a circuit things don't make sense.  Example, the crystal filter. Injecting a signal starting from the output end, going through the amplifier, successive stages of the 4 xtalls and then another amplifier, a signal is heard.  I may question the amount of signal lose thru the xtalls, but that's another issue for later. But the signal does not get thru the input capacitor. Seems a simple problem but not so as it turns out.  The cap is not shorted to ground or internally. I measured the capacitance with my AADD meter and it appears all's well. Yet the signal does not get thru the cap.  And on it goes. So, onto the next hobby for a day.

Lets make some beer.  I've been wanting to make some beer for quite a while now and over the last couple of months, I've purchased all the equipment. Well, I still need to go out and get the co2. I decided to not to bottle the beer and go to a draft system instead.

I had made a fair amount of beer of the years, but not in the 20 or so.  I was pretty much starting over again and it certainly felt that way preparing all the ingredients.  I steeped my own grains and cooked the batch for an hour on the stove. Someone nameless said I assaulted their sense of smell during the process, but I thought it smelt quite nice in the house.  Beauty is in the eye of the beholder I suppose. hihi.  Not many problems arose, but as in my adventures in electronics, a couple of oh ohs. 1, I put a little too much water in and the og is a little low. 2, put the yeast in and the temp may have been a little on the high side. And 3, over cracked the grains. 

I suspect and hope nothing major, as the batch is bubbling away quite nicely. Now if I can get a decent taste and as a bonus, since its an Irish stout, head on the final product. A homebrew solution to aid me in solving my other homebrew issues.  Cheers!

PARC 50 LBS 1st Final Version

1st Final version? Well this truly is a breadboard based project.  And to that end, I've designed it to be very adaptable to what ever improvements(?) I can come up with. This is why I built large, spaced out boards. So, this will be the layout to start with and pretty much marks the conclusion of the Lets Build Something project that was presented in QRP Quarterly by Pete Juliano, N6QW, and Ken Kuo, KK6FUT.

Along the way I expect to learn a great deal and end up with a solid understanding of the individual circuits involved in transceivers. Oh, and of course, lets not forget that the first contact is right up at the top of the list.  Even better would be a 2 way QSO with another LBS rig.

Still to complete and the last on the list is the tx/rx/bypass board located in the lower left area. I have 1 relay on hand and the other on order. Still a couple of weeks out for delivery, but you never know. I'll likely put in the 1 relay I have on hand now so I can continue with at least the ssb rx mode.

I've just finished up wiring the 12vdc supplies. I contemplated a couple of ways to distribute the 3 different categories, 12v constant, 12v on Tx and 12v on Rx. In the end even though it takes more wire, I ran each board back to a main distribution board.  Combining boards would reduce the mess and I don't think it would take much thought to reduce even further. However this style suits what I wanted to accomplish. I may regret all the molex connectors I installed, but 1 problem at a time.

Now to power it up. Always an adventure....even though I have previously powered up all the boards individually.  I think I'll admire for just a little longer first. hihi. Do not want to increase my status in the "I Let Out the Smoke Club" at this point.

PARC 50 LBS

Getting closer to completing the first stages of the build now.  This is when you realize that you forgot something or wished you did some things differently. In this case while trying to layout the various 12vdc feeds, of which there are 3 types,12v continuous,  12v tx, and 12v rx. I decided to etch yet another board for the 12v feeds. There is 1 spot left on the layout board that can be used, but there are better locations if more thought had gone into this at the beginning.  That's how one learns I suppose.  hihi.  Needed to move the 2 pin connector on the right to a new location as the original spot was too close to the 6 pin connector.  Hence the funny angle.

Another problem came to light when testing the rx in direct conversion mode.  There was an annoying, pulsating, noise in the audio.  The rate of the noise followed the tx led located on the arduino board.  Eventually I was able to trace the problem to 13 lines in the source code.  They were serial print.ln functions that were used for code testing purposes that sent various data to the serial monitor.  I've theorized that since the serial port was open, no cable attached, that the noise emanated from this port and got into the audio amplifier.  Commenting out those lines cured the problem, I have not tested the serial port theory as the noise is gone and I've moved on. One day though.

Direct Conversion Mode for the LBS project

I decided to connect up the appropriate boards for the DC receiver mode.  Up until now I had only injected rf from a signal source and was happy with that.

Of course nothing has gone smoothly so far and the trend continued here as well.  I might add that all the issues (except for maybe 1 or 2) experienced were careless errors on my part.

For the DC mode setup here were my errors this time:

Grounding switch for the DC mode not wired correctly
BPF put in the wrong position
Fed the antenna into the output of the rf amplifier

Its a wonder I haven't let the smoke out at some point in the project.

Anyway I finally got it up and working.  I'm sure I'll be doing some changes, but I won't worry too much about the mods until the final version is all up and running.  For sure some audio work will need to be done.

Picture is the boards used for the DC mode.  RX amp, BPF, Mixer, DDS control, and not in the picture, audio amp.

PARC 50 LBS

Finished etching the Tx/Rx and Bypass relays board. Unfortunately I had to order some parts and will need to wait before I can populate the board however.

This gives me time to clear up some loose ends and to that end, I worked on the mic amp board. Calculated the dropping resistor for the bias on the mic circuit, adjusted the gain somewhat, but I'm not all that happy with the tone quality I was hearing from the mic through the audio amplifier. Is the issue in the amp and the mic circuit or just one area? Looks like a little reading up on tone circuits will be on the agenda.

Re did the layout again.  I think I have all the boards down in their final positions.  Below is a picture of all the boards including the latest relay board.

Preliminary adjustments to the finals went well. Mainly because I did not let out any smoke. Got nice and hot during the first power up, but everything survived.

To do list:
couple of connector decisions to be made
layout of the antenna connector position
power supply cable layouts
PTT cable
VFO and BFO cabling

That's pretty much it....I think. I'm positive once powered up after all the connections are made the list will grow.  But that's alright. How else will one learn.