Frequency discriminator and all-electronic receiver

[Mike(Mont)]

Been working on this almost everyday since last Summer. I don't claim it to be my design but the majority of the parts are of my doing. I've streamlined some things and cut out the fat--stuff that is not really of much use. The idea is to keep the price under $1000 for the system. I've got a working model but it's held together with rubber bands in a cardboard box. So I need to get an enclosure, etc. but my problem is I can't stop working on it. I thought for a while I was going to stop, but not the case. So the journey continues. Kind of a love-hate deal here. I love to make improvements but i hate to not have it done. At least I think i do. Hell, i don't know anymore. Bordering on obsession. i ain't crazy, i don't think, but maybe i am. Some day I will commit to the final version. I hope.

[Mike(Mont)]

Well, I came back to my senses and decided I'm not going to pursue that tangent I almost flew out on yesterday. It would have cost more money and not much if anything to show for it. So for now unless I go temporarily insane I won't be messing with any more changes to the basic design. But never say never. And besides, I have other stuff I feel is going to be necessary to make the thing marketable if I go that route.

[Mike(Mont)]

I just bumped the accuracy of this thing up a whole 'nother level. I could say it's just because of Winter conditions but that's not the case because i was using it, then made the changes and the improvement was immediate. Well, I've said that before about a few hundred times. But that's mostly been with L-rods which are so hard to accurately analyze and evaluate because it's mainly operator skill. There's some operator skill involved with the electronic receiver, but it's not such a main factor. So I'm saying it is a big improvement. Well, still have to get it out and find some real targets before I crow too much (or is it EAT crow? ). That's months away. Hurry up Spring!!!

[Mike(Mont)]

If this holds up I don't think L-rods will be of much use. i don't know for sure how it will act when the thunderstorms return. I've always noticed better locating conditions in the Winter months. Don't know if I can wait that long.

[Mike(Mont)]

I've been flop-flopping like a fish out of water over the receiver antenna. As much as I like the litz wire loop antenna, I found it easier to house the ferrite rod so for now I am building with the ferrite rod and see how I like it. I don't know, I guess I should build both types and then compare them side-by-side. They both work fine but I want whichever looks nicer.

[Mike(Mont)]

It's not as pretty as i would like, but it works better than I expected. The receiver antenna is a pistol type design made with PVC fittings. I want to find some different parts just to make it look nicer. But I am very pleased so far and it makes it much easier to use and point now--I originally had it in a thin cardboard cracker box, very floppy. This is getting darned close to completion. It's been a lot of purgatory time, but it has become a part of me--kinda fallen in love with it. I plan to put the receiver electronics is a box and hang it from my belt. Shouldn't be too much bigger than an old transistor radio. Of course the transmitter sets on the ground.

[folharin]

Good luck with your project expect good results

[Mike(Mont)]

Thank you very much. I've been using it in my yard on a practice target and most days it has been working very well. Some days with the big solar flares it doesn't lock on to the target as well, or takes longer time. What i am finding out is pretty much everything Dell Winders talked about. It's so much harder to see that with just a set of L-rods.

I know with L-rods I would get a signal line, but actually I know now it was not the exact line. As I got near the target i would notice I had to move over one way or the other. With the electronic receiver I can see immediately if I am on the line or not. And many times it is off some, especially during the bad conditions but also within the first few minutes. It just takes a while to lock on, usually about three to five minutes. this is one of the main reasons I tell people the hand-held frequency discriminators can't be expected to work well or maybe not at all.

[Mike(Mont)]

I have a few loose ends to tie like the enclosures and the transmitter antenna coil former, but everything major has been worked out. I'd like to say "It's done!" but I know all the small details are going to take some time to finish, like a few weeks at the pace I am going. I know there is always hidden stuff that pops up when least expected. I can see the light at the end of the tunnel and I feel very much relieved like i got the monkey off my back. I don't know if if you can feel that sigh of relief. Feels good.

[Mike(Mont)]

Disregard the last post. I am not done just yet! So i will build and test it today.

[Mike(Mont)]

Torn between two lovers...

My head is spinning right now. On one side the ferrite rod works great for nulling and has more power, on the other side the loop antenna works great straight on and has much less chance of breaking if dropped. I like the ferrite rod better. Decisions, decisions.

[Mike(Mont)]

After a rough night of trying to "sleep on it" i have decided to go with the loop antenna. It points better and is more durable. Well, at least for now.

[Mike(Mont)]

I'm going to change my wording and say "It's undone!" Kinda like the Unbirthday on Alice in Wonderland. And probably very close to the truth! The more I work on it, the better I like it. Why should I stop now? It seems just about every day I come up with another improvement and I guess i just need to "let the fever run its course". And it's burning right now.

[Mike(Mont)]

Well, I am here today to attest to the fact that bias and ego can really affect a person's judgement. It is so easy to let it creep into your work. I've been through many trials and tribulations or what refer to as purgatory time over the receiver coil I'm trying to get right. Every time I think i have it right, after much testing if find some aspect that is just not good enough. My latest "find" is that the air loop coil I thought was so good turns out it just does not work well out on the edges of the search zone. I came up with my version of a Chinese proverb: "Man who pats self on the back ends up with broken arm."

Anyway, i went back through most on my designs trying to find "something". So now I'm back working on a spiral coil. i had tried one before and thought it was too weak, but it does work. So I need to work with it and find out more about it. I'm just so slow. I usually take a whole 24 hours to be able to analyse the results, and I wake up the next morning with an understanding. It's getting there but it sure is slow. Like they say "Love is patient."

[Mike(Mont)]

I don't know anything about spiral coils. I guess I'll just have to build a few and do some testing to see what I like. Think I'll use some bell wire with the plastic insulation because it looks to be easier to work with than magnet wire. But I suppose I'll have to use that, too.