Field Day and Homebrew Rigs. (well I did put the kx3 together)

I took the KX3, SW40, and the LBS rigs to the Kingston Amateur Radio Club’s (VE3KBR) Field Day located this year on Wolf Island.  Great site, great bunch of guys, and a great time.

I made 36 contacts with the KX3, but it was tough getting through the pileups (ya think?) with 5 watts.  It got much easier Sunday afternoon in the last hour for some reason and was nice to work a few in a timely fashion.  I fired up the SW40 and though I’d give CW a go. That was a laugh. I’ve never heard so many cw signals at the same time and all way too fast for my ability.  I thought I could spent a couple of minutes and get all the information and then jump in.  I’d have been happy with one contact but it was not to be.  However I did get one contact that I’m extremely happy about.  The LBS rig is alive and well.  I managed to get one and encouraged, I tried for more, but to no avail.  There were a couple of partial attempts but I was really too weak.

Now that I’ve managed to prove the rig is working, I wonder how well I sounded. I wish I thought about it more and had my phone ready to record the QSO just in case but to be frank about it, I didn’t really expect anyone would hear me. I kind of suspect that during Field Day people put up with less desirable signals than during the course of a standard QSO.   

So up next is to try and check into the Trans Provincial Net and get a signal report.  From there it will be to decide the next steps to take in the LBS design.  Other than the pre-amp for rx, it is built as outlined in the original article.  Well I suppose my construction technique is different as well, but the circuits built are as designed. 

Software improvements and the big challenge, board designs. All things to think about with a cool one in hand. Hmm, that's a good idea.

73, Peter

A Great Day in the Shack with my LBS Rig.

This has being one long project and this is just to get it working.  I want to eventually get around to modifying some of the boards in order to learn in greater detail the various circuits. Eventually put it into a case and go from there.

Somehow I finally have been able to adjust and minimize the carrier, get rid of the noise on tx and adjust the various tx levels to the point where I can put a decent signal on the air.  At least I think it’s a decent signal.  Here is a link to an audio file of the transmission I did an hour ago:

https://dl.dropboxusercontent.com/u/97743994/LBS/LBS%20June%2022.wav

I backed off the mic at around the count of 10 and the audio clears up. There was some background noise in both the shack and outside where the KX3 was located to receive the LBS signal. I’ll do another recording later keeping the background noise in mind. I’m sure I still have some tweaking to do but at least I can now move forward.

As well I’m not completely comfortable yet with the carrier adjustment, but I was able to substantially reduce it and will make some more accurate measurements. In fact measurements all the way round.  I started a document to capture schematics, build notes etc, but got away from it with all the issues I was having.

So it’s looking like I might be able to give the rig a go during field day. Great day in the shack.

73, Peter

LBS Rig Noise Update

Well, that was fun.  I found 2 flaky sma cables, one bad power pin for the relay 3 board, and a loose power pin on another board.

The shack and the rig is a big mess. Wires, test gear, parts all over the bench. In fact I spread out over 3 benches.

The good news is I think I’ve licked the noisy signal issue.  Got rid of all the 12v return lines and the ground loops and go figure… no noise.  The carrier adjustment is better as well.  Not quite so sharp.  I don’t like the fact that the shield is no carrying the 12v returns to ground, but I didn’t have much choice.  

The design of this rig was chosen so I could easily replace individual circuits/modules as I learned about them and may have made some improvements in the design.  I didn’t realize at the time that the design would create problems. Ie the ground loops.  Another problem I found was my choice of rf cables.  I went with pre-made sma cables and that was not a good idea.  They are not the best when used in tight spaces.  Sharp bends and loops are needed and this has put pressure on the connectors and this has made for intermittent connectivity.  Next time I’ll make my own cables and use RG174.

So tomorrow I’ll set up my KX3 again in the backyard and record the transmissions from the LBS rig.  Last time lots of evidence of ground loop noise and this time, let’s hope no noise.  Preliminary testing suggests no noise.

Here's a picture of the LBS rig in its present state.  If it proves to be quiet, then I'll clean up the cabling.