10G Quick Beacon Is Back! And a big channel announcement.

[00:00:00]Hey everybody, welcome back to the N1BUD channel.

[00:00:04]For those who don't know, my name is Paul. Ham radio is the game and the major subject of this channel.

[00:00:09]I want to start out today with an apology and a major channel announcement. Or maybe a couple of announcements.

[00:00:16]Uh first of all, it's been a long time since my last video and I know in the last one I promised there would be a new one out soon and because of limited resources both financially and time uh soon turned out to be uh quite a bit later than I expected. But here we are, we do have a new video today. Uh new project Well, not a new project, a new video on an old project to to do.

[00:00:41]Uh some of you have been with the channel for a while may remember Quick Beacon or QB for short, my second attempt at a 10 GHz uh beacon.

[00:00:50]The first one having run into some difficulty that I was unable to get past. So QB is a quicker and dumber uh beacon to get something on the air as quickly as possible and still it has taken forever.

[00:01:05]Um I do want to acknowledge a North Texas Microwave Society for a generous uh financial contribution to the Quick Beacon project.

[00:01:15]This project would absolutely not be making any progress this year were it not for that because I have no funds to put into it of my own.

[00:01:24]I have a lot of other things going on that take precedence over ham radio right now, unfortunately. I wish that were not so. But thank you very much, North Texas Microwave Society, for your generous contribution to this project and I am very, very grateful and very excited to have QB uh back on the bench and uh well, technically it's on a pole over here behind me, not really on a bench.

[00:01:46]Uh but you know what I mean. So hopefully it will be up uh very soon. So we're going to talk about QB and what's going on with it uh today in this video.

[00:01:56]I do have another announcement, however, uh because ham radio is taking a backseat to so many other things lately.

[00:02:04]I am starting a new channel which will be called N1BUG on the loose.

[00:02:10]Kind of a tongue-in-cheek or humorous channel name there.

[00:02:14]But it's about every other thing that's going on. It may be about working on some content there. May be about working on my two old garden tractors which are kind of a necessity for me and also a bit of a bit of a passion.

[00:02:27]Some of it may be about hiking and exploring local places.

[00:02:32]Any number of of other activities besides ham radio. And I should be able to put out a lot more content on that channel.

[00:02:39]Because I spend a lot more time these days doing that stuff than than radio.

[00:02:43]Again, wish it weren't so.

[00:02:46]But I'm afraid it is. So, right now there's no content over there on the new channel. Again, N1BUG on the loose.

[00:02:55]But there will be content coming very soon.

[00:02:57]So, I don't know that many of my viewers here will be interested in that. But if you are, check it out in a few days here and I'll try to put up another announcement here on this channel when there is stuff over there.

[00:03:11]Um But I expect for the most part that channel will have to attract its own audience. I don't expect many of my viewers here to be interested in my other activities. So, I will just see how that one goes. It's just something to do and to augment some of the other things going on in my life right now as this one has augmented my ham radio activities over the last several years.

[00:03:37]All right. So, without further ado, let's get back to talking about the quick beacon project. I'm going to get out from in front of the camera here and get behind the camera and show you all what's going on with it and what I'm doing with it today.

[00:03:55]So, as I mentioned, QB is set up over here on a pole.

[00:04:00]A little metal pole here that's kind of attached to an unfinished wall here in the workshop.

[00:04:07]Um and I apologize for the crudeness of all this. This is This is whatever works, not whatever looks good on camera.

[00:04:16]Uh I just want to get this done. I want to do quality work, of course, and take my time, which I am, but I just want to get this done. I don't want to be fooling around forever making the working setup look pretty. Sorry, guys, but I'm more into making progress, but I do want to share it all with you. So, here's QB, Quick Beacon, set up over here.

[00:04:37]Just for a little bit of review, here's a look inside. It's been a while since we looked in here and talked about this.

[00:04:42]There's been a couple changes.

[00:04:45]So, right now, QB uses this 10 MHz OCXO as a frequency reference to keep the synthesizer pretty much on frequency at 10 gigs.

[00:04:55]There's the VHF design synthesizer that generates the 10 gig signal and also does the CW keying for the beacon.

[00:05:03]Uh arguably puts out about 10 mW, but I think it's probably about half that in reality.

[00:05:09]Um I don't know.

[00:05:11]Anyway, that generates the signal. Then there's an attenuator to knock that down. I think it's a maybe a 12 dB attenuator or something like that, maybe 15. It knocks it down to about minus 7 dBm to drive this little quarter watt um uh driver amplifier down here.

[00:05:31]And then the output of that comes up into this 2 W amplifier, and then from there we go out into an isolator, and then from there into the antenna.

[00:05:40]Normally, right now I have a directional coupler in here cuz we're going to be making some return loss measurements, which is what we're going to talk about primarily today.

[00:05:48]I have the quick beacon or QB power supply and um monetary unit down here. There are some unique things about QB that are probably uh stupid use of extra complication.

[00:06:03]Uh you know, it violates the KISS principle, keep it simple stupid. I didn't keep it simple.

[00:06:10]I wanted some way to monitor the health of the beacon, particularly um this very old uh 2-W amplifier if possible without climbing 100 ft up the tower where a QB is going to be mounted.

[00:06:24]And um you know, wire and cable is very expensive these days. As I said, I'm on a shoestring budget when any budget at all. So, I needed to limit it the number of conductors going up and down the tower, but also have heavy gauge wire for keeping voltage drop under control.

[00:06:43]So, the original beacon would have had an Arduino uh beacon keyer for the CW message in it and some sensors and it would have been able to add telemetry on operating parameters such as the DC voltage output from the PA propor- proportional to RF power on the beacon message. This one cannot do that.

[00:07:05]So, I wanted another way to do it. So, I am using a four-wire control cable going up the tower, a positive and a negative power lead going up, and then another voltage sense lead coming down to read the actual power voltage at the beacon because we have we don't we're going to have some voltage drop in the uh 150 ft or so of of cable uh power cable getting up here.

[00:07:30]And then also a fourth conductor which will read the which will have the voltage from the DC output here on the PA which is proportional to RF power uh back down to the power supply and monitor unit.

[00:07:43]There's an Arduino in here, an Arduino Nano, and some um voltage and current sensors that will read out the operating parameters of QB on a display here.

[00:07:57]And that'll be the um power supply voltage as it is here down in the building, power power voltage at the beacon, uh current draw of the beacon, and the PA RF sense uh output voltage.

[00:08:13]Uh so, we will talk more about that here um probably a little bit later, but that is the crazy setup for a quick beacon.

[00:08:22]Now, what's left to be done with quick beacon is a couple of things. Uh one thing I want to do some minor tweaking of this Arduino code for the monitor we just talked about, but that's that's pretty minor stuff.

[00:08:33]I need to choose a radome to enclose the uh slot antenna up there to keep uh you know, water out of it and bugs out of it and and whatnot.

[00:08:42]That's a little bit of a problem because available radome materials are probably RF lossy at 10 gigs and will probably also affect the antenna SWR or return loss.

[00:08:54]So, um that's going to be today's testing. I also uh am going to be putting a GPSDO in here so that I will have the option of either using the OCXO or GPSDO for frequency locking the beacon. And I intend to run on the GPSDO. The OCXO is here as a backup or an option should I ever need it. Right now, I am using the OCXO. Uh the output of the OCXO come loops around here and goes back in as the reference to the synthesizer.

[00:09:24]Uh so, I need to add the GPSDO. Most of that work is already done. It's just it just needs to be mounted in here and sealed up, you know, so water can't get in and and so forth. Um So, that's yet to come. But, rate on materials, um ultimately, the best I can do really is PVC pipe. So, the trick is to select which one has the lowest loss. I've got three samples over here.

[00:09:49]I've got a piece of standard schedule 40 plumbing grade PVC. I think this is Charlotte pipe. Um I think it was the manufacturer. It doesn't say on this piece.

[00:10:00]I've got a piece of furniture grade, um uh PVC here, which came from, um still again, 2-in and I think this is schedule 40 or the same dimensions.

[00:10:10]Came from Formufit, which I bought ordered online.

[00:10:14]So, the wall thickness on both of these is about 0.154 in.

[00:10:20]Uh then I've got this piece of ultra thin wall, uh class 125 or SDR 32.5 PVC pipe.

[00:10:30]Again, 2-in nominal size, but this has a wall thickness of less than half of this. This is nominally 0.073 wall thickness.

[00:10:39]So, I want to see which one of these affects the return loss on the beacon the least or messes up the antenna SWR the least.

[00:10:47]I cannot measure the RF losses of these.

[00:10:50]We've been out down that road before. I think there was a video on it that completely failed. I just cannot come up with a test setup to measure or even estimate RF losses in these materials.

[00:11:01]So, I'm going to naively go with the one that has the least effect on the return loss and call it good. That's I hate that.

[00:11:09]I'm not that kind of guy. I want to know what the performance of stuff is, but I just don't have a way to know, and I don't have a real way to use other materials. This is what I have. I got to make some of this work.

[00:11:21]Because a beacon that doesn't work as well as it could is better than no beacon at all as a number of people have been trying to tell me now for the past couple years that I've been uh dwelling on this uh problem of of the losses in the radome materials.

[00:11:38]So, that is what going to be what today's test is all about. So, I've got the um the uh directional coupler, 20 dB directional coupler in here in line, and I'm just using the output of the driver amp at about a quarter watt for this.

[00:11:51]That's uh that's enough power for this testing. I don't need to be frying myself with a couple of watts of 10 gigs RF right near my head up here, and and if I did that, I'd have to use an attenuator to knock the level down enough for the uh HP 432A uh power meter over here we're going to use for these for these tests. So, we're going to measure forward power and reflected power with no radome, like it is now, and then with each of these three radomes, we're going to record all the numbers, and we're going to see which one has the uh least effect.

[00:12:21]So, actually, I've already done that, and I am not going to walk you through all uh eight of these tests. Uh two, you know, forward and reflected power with uh no radome, and then forward and reflected with uh each of these. That's eight separate tests. That's a lot of flipping this directional coupler back and forth.

[00:12:42]I'm not going to make you suffer through all of that.

[00:12:45]I will show you uh one test, and all the others are just the same with a different uh different radome on here. So, um and that's, you know, that's what I'm going to do.

[00:12:56]Cuz it gets very repetitive. So, uh I'm going to try and set up the camera here somewhere um on a I guess this it has to be filmed in a few segments. So, some of it with the camera handheld, and some of it with it on a tripod as I'm working here.

[00:13:13]So, uh let's choose to do the ultra thin wall. So, I'm going to choose uh this radome here, and I'm going to uh slide it over the antenna here, And down into the uh uh flange here. Try to get it down in there all the way and nice and square with the antenna.

[00:13:37]And so there we have a radome. Of course, there would be a cap on top, which I expect will have no effect on S- on SWR or return loss because it's above the radiating portion of the antenna.

[00:13:47]So, so that's what the radome's going to look like.

[00:13:52]So, right now we're set up to measure forward power.

[00:13:56]Uh we're feeding power into J1 on the directional coupler.

[00:14:02]J2 goes to the antenna or the load uh or device under test.

[00:14:09]And J3, which is a minus 20 dB coupled output, goes down through to the HP 432A um wireless power sensor for the HP 432A and over across to the meter itself there.

[00:14:25]So, right now we have the meter on a scale of max full scale plus 5 dBm.

[00:14:30]And it's all zeroed and everything and ready to go.

[00:14:34]So, I'm going to go ahead and uh flip on the beacon.

[00:14:37]>> [sighs] >> And um it'll send some CW first and when it stabilizes and sends a steady carrier, we'll take a a forward power reading here. So, I'm going to go ahead and flip this on and it uh comes to life over here and uh does its thing, I think. Um So, it is sending CW right at the moment.

[00:15:08]Okay, so there's the key down and we're seeing a reading of minus 3.

[00:15:14]4 right there on this scale, on this bottom scale, minus 3.4. Now, we can talk about what that reading Let me just go ahead and shut the beacon off. Um So, full scale on on this scale is +5 dBm.

[00:15:33]And that would read zero on this meter.

[00:15:34]So, it's +5 dB +5 dBm minus 3.4 dB.

[00:15:42]So, uh five minus 3.4 is is uh 1.6.

[00:15:53]Did I do that right? My math skills are going downhill, but I think so. 5 minus 3.4. This is embarrassing. Yeah, 1.6 dBm.

[00:16:04]Sorry, folks.

[00:16:06]It's been that kind of a day. Um so, forward power with this radome is uh 1.6 +1.6 dBm.

[00:16:18]So, I've noted that on my sheet of paper numbers over here, which we'll talk about a little bit later. So, let me go set up the camera that on a tripod where you can watch me flip the directional coupler around, and then we'll take a reflected power uh reading.

[00:16:32]Be right back.

[00:16:35]Okay, so I think this setup will uh will kind of work here where I've got the camera where I got you guys.

[00:16:42]So, what I need to do to measure reflected power is I need to flip this directional coupler around the other way.

[00:16:50]So, what's the input becomes the output and vice versa.

[00:16:53]Um now, I don't want to twist any cables in doing that, so I'm going to loosen up this one on the uh coupled port here uh so that it can kind of pivot, and I won't be twisting the cable as I flip this around.

[00:17:06]I'm going to go ahead and take the input completely off cuz it needs to go on the other end.

[00:17:13]Get the output completely off cuz it's going to end up on the other end. I'm sorry my hands are in the way. Can't really can't really do this any other way. So, it was that way.

[00:17:23]And I'm just flipping it end for end.

[00:17:26]Put it back on here so that the what is now the output connects to the antenna.

[00:17:34]Put this uh input power cable on what's now the input.

[00:17:41]Get it lined up here.

[00:17:50]Trying not to get my head in front of the camera here, but uh I'm uh apparently struggling a little.

[00:17:58]Hopefully my head isn't uh in front of the camera. I actually don't know that it isn't.

[00:18:03]I'll have to check the uh video here in a minute and find out about that. So, I'll get that one tightened up.

[00:18:09]This one tightened up.

[00:18:12]And retighten the one that I loosened so it could pivot here.

[00:18:16]Carefully.

[00:18:17]Okay.

[00:18:18]Now we are set up to measure reflected power.

[00:18:23]So, I'll grab the camera here again and we'll flip the beacon back on.

[00:18:28]And uh I'm going to reach over here to the meter actually and put it on a different scale because we know there's going to be a lot less uh RF power here.

[00:18:38]Now.

[00:18:40]Again, I've already done these uh these readings once, so I kind of know what to expect on this.

[00:18:46]And sorry I'm over here fiddling with the meter and probably uh my voice just got kind of kind of funky on you all there as I was away from the camera. So, I'm just Okay, so now we're set up to measure reflected power.

[00:18:57]And I'm going to turn the beacon back on.

[00:19:02]And uh it's uh booting up right now and there it goes uh doing its sending CW thing.

[00:19:12]So, uh we will see what we get here when it goes uh steady state key down.

[00:19:20]All right. So, we've got -1.6 on the meter scale.

[00:19:26]And it's at -15.

[00:19:29]So, the zero point is actually -15 dBm.

[00:19:31]Let me go ahead and turn the beacon off.

[00:19:35]So, -15 -1.6 is minus So, -16.6 All right.

[00:19:50]Yeah, minus um Math is not my thing today.

[00:19:57]So, yeah, minus uh 16.6.

[00:20:02]So, and then we had plus uh What do we have? Plus 1.6 um dBm before, so 16.6 +1.6 is a return loss of 18.2 dB.

[00:20:24]Which strangely is not what I got before.

[00:20:27]Let me think about this and I'll get back to you.

[00:20:33]Okay, folks. So, guess what?

[00:20:35]10 gigs RF is being 10 gigs RF.

[00:20:40]Flaky as can be and you can't get the same reading twice. So, So, let me go over what I've got here.

[00:20:47]I've been over all of these measurements a few times now off camera.

[00:20:51]First of all, the forward power readings are very consistent within you know, a fraction of a dB.

[00:20:59]Uh like 3/10 of a dB or so with without a radome and with any of the other radomes, I can go through it multiple times and the readings are all, you know, very close.

[00:21:09]Um so, that's good.

[00:21:11]With the radomes, however, there's some variability in the readings on reflected power.

[00:21:18]So, with no radome, it's pretty consistent. My first run I had uh -19.8 dBm.

[00:21:26]Then I had a -19.4 and two -19.6's.

[00:21:30]So, that's, you know, pretty consistent within a 4/10 of a dB.

[00:21:35]With the ultra thin first reading was -13.5 dBm reflected power.

[00:21:41]Then I had this anomalous -16.6.

[00:21:45]Then a -14.5 and a -14.2.

[00:21:50]And with the plumbing PVC, I had -12, -11, -11.6, -11.4.

[00:21:56]And with the furniture grade PVC, I had -9.8, -11, -10.3, -12.

[00:22:02]So, there's a couple dB variation in some of these and it seems to be that it's sensitive among other things to exactly how the radome is sitting on here.

[00:22:13]Uh you know, when you put this on here, um you know, you can still tilt it back and forth a little bit depending on just how you have it sitting down in there.

[00:22:24]And it is sensitive to that. It changes the uh reading a little bit.

[00:22:29]However, what I can say with confidence is that all of the radomes do affect the return loss or degrade the SWR.

[00:22:44]The one that affects it the least is the ultra thin wall.

[00:22:50]The one that affects it the most, um it's really a pretty close tie overall, I think, between the plumbing and the furniture grade. Uh but clearly the ultra thin wall is consistently affecting it less than the two thicker wall options.

[00:23:10]So, while I hate everything about this not really knowing what the performance is, I'm just going to choose to go with the ultra thin wall, put it on there, put the beacon up, and run it.

[00:23:25]And I'm sorry, that's the best I can do. I just don't have the facilities to measure the losses in these and and the return loss measurements are very finicky because of the exact positioning or tilt of the radome with respect to the antenna.

[00:23:43]But, I'm pretty confident that the ultra thin wall here is having the least effect on the return loss. And it's not horrible.

[00:23:53]Um You know, I have to go run some of these other numbers. My initial one with the minus 13.5 dB uh, return reflected power reading was an SWR of about 1.42. So, SWR with no radome was 1.18.

[00:24:10]With the ultra thin wall, it was 1.42.

[00:24:13]And then with the others, it was it was a little higher.

[00:24:16]Um, but all of my readings after the first have been a little better here.

[00:24:21]So, it's likely a little better than 1.42, maybe around 1.3, 1.35, or something, which uh, you know, really isn't that bad SWR wise or return loss wise.

[00:24:31]Again, don't know what the actual RF power lost in the radome is. But, that's the deal.

[00:24:36]Going to go with the ultra thin wall. I hate the fact that I can't do any better with these measurements, but um I've done all that I can.

[00:24:46]So, I'm going to end this video there today.

[00:24:49]And um over the next couple of couple of three days, there's probably going to be some videos posted on my other channel that I announced earlier and one BUG on the loose.

[00:25:01]And within hopefully within a week um I hope within a couple days, but let's say within a week we'll be back for some more QB work here on this project and try and get this thing wrapped up and get it installed on the hill.

[00:25:18]And I'll try to do some videos about the actual installation work and so forth, too. So, stay tuned if you're interested in this project.

[00:25:26]Uh if you want to see what else I'm into, check out my new channel in a few days and uh next time we meet here on this channel, I'll let you know if there's content up there yet. There should be maybe even starting tomorrow, but uh we'll see about that. So, thanks guys.

[00:25:41]Thanks for Thanks everybody for watching. Uh please like and subscribe if you haven't already.

[00:25:46]And we'll see you back for the next video. Bye for now.