Here's video from the TAPR conference last fall in Atlanta, the 2nd half is about the 44. subnet:

http://forums.qrz.com/showthread.php?371945-HamRadioNow-APRS-APRS-and-even-more-APRS-from-the-DCC

Don't forget about a collinear vertical if you're going to the effort of putting up an outside antenna. Good gain and still omni-directional. Most are dual band 2M/70CM as well. I had one up about 20 feet at my old QTH and could hit repeaters 60+ miles away easily.

You have the audio into the computer set too high, or the gain on the microphone input too high (or some combination).


If you turn down the audio input the squelch will start to work. As you make adjustments watch the scope and you'll see the signal lines start to look "right." The PSK 31 scope is a vectorscope (phase display). When you are tuned properly the green line with flicker between 0 and 180 (12 and 6 o'clock) on the scope.

http://www.w1hkj.com/FldigiHelp-3.12/DigiscopeDisplay.html

 A few basic questions, please don't be offended.

1) What color is the majority of the waterfall display? It should be mostly dark blue/black, with signals showing up as bright yellow or red tracks on specific frequencies.
2) Open the signal scope (view, digiscope). In RTTY mode it should be a square with crosshairs in the center. If it is 3 horizontal lines (2 yellow and a green in the middle), click on the actual display and it will change to cross hairs. This will help you properly tune the radio to the signal. When it is tuned properly you'll see green "traces" on the display looping around the crosshairs. Off frequency the loops will be at a different angle or random lines.
3) make sure you are in the right mode. I think RTTY45 is the most used mode.
4) You are using the cursor on the waterfall to "tune" to a particular QSO, right?
5) You can stop the random characters with the squelch control, next to the green signal meter in the lower right hand corner. It doesn't need to be very high. Too high and you'll miss a lot of weak signals, too low and you'll get random characters.

Well, if he has a general coverage receiver and can tune it to 149.75MHz he has a good chance of hearing ch18's sound. That would tell him there's a leak in the area. Depending on where that leak is, it might be huge or might be minor. Most HTs will tune outside the ham bands these days, so it wouldn't be very hard to check.

Maybe I did jump the gun, but if you're not getting the level of service you're paying for, call the company and get a service call scheduled. There's no excuse for slow speeds from your ISP these days, Internet service is a mature industry (I've been doing this since the mid 1990s, nearly 20 years {wow that makes me feel old!}) and there's a ton of lessons learned and knowledge built up over the years.

Cable ch 18 is centered at 147MHz. If your cable company is using ch 18 for an analog signal you should see a video carrier at 145.25Mhz and hear a wideband FM audio carrier at 149.75. However, many cable companies have been converting their analog video channels to digital in order to offer more services using MPEG 2 compression. In that case ch 18 may be a QAM carrier, which uses a mix of phase and amplitude to send a datastream to a receiver that can demodulate and decode the signal into digital data (and ultimately a picture). These signals resemble wideband white noise due to their nature (they are sometimes referred to as a "haystack" because of how they look on a spectrum analyzer). QAM signals shouldn't necessarily produce a discernible signal on an analog receiver, just an increase in white noise.

If you are able to see or hear an FM carrier, it would indicate that there's a leak in the cable nearby. It might be in your house, it might be on the street, or even in your neighbors' house. If you're able to pick it up it's likely close by, because even with an ideal radiator it's only a few dB of signal output, and most leaks are far from ideal (although I've had a few that traveled for blocks when the lashing wire on overhead lines touched the center conductor on a cracked hardline).

If signal can get out, noise can get in, so it could be possible that your modem might be suffering from ingress. I doubt they use ch 18 for the cablemodem downstream carrier, basically because we know there's ham radio and other land mobile stations in that part of the spectrum (along with some other reasons not relevant). Usually you can check your modem settings by opening a web browser and going to http://192.168.100.1/ and checking for a "signal" or "status" page that should tell you what frequency is in use for both upstream and downstream, along with a signal quality measure called MER (should be better than 30dB for error free communication). But ingress is usually very broadband in nature and because of the proximity of powerlines and transformers it doesn't take much to trash the cable signal. So if you are seeing problems with your modem it woudn't hurt to call and see if someone can come out and check to make sure things are OK. Don't try to explain leaks or ingress to the folks at the call center, they most likely won't understand, but feel free to discuss with the tech who comes out to investigate. They should have leakage detection equipment on their truck that can help narrow down any problems.

Good luck.

Sort of like when I can't find something that I just saw last week. Then it turns up after I stop looking for it (usually when I can't find something else). I blame quantum mechanics!

Somewhat off topic, what is the general opinion of using a 100A battery tester to check station backup batteries? I have an old telecom gell cell (http://www.mkbattery.com/images/E31%20SLD%20G.pdf) that will run my entire station for hours if needed, but I rarely run it down much. Once in a great while I'll throw the battery tester on to make sure it still holds a charge, but I'm sure there's a better way.

It's basically a resistive load with a volt meter and switch to cut in the load, made for automotive SLA batteries.

I did a little more checking and came across this:

https://www.argentdata.com/catalog/product_info.php?products_id=134

Don't know how easy it might be to interface, but it will change frequencies with a command from a microcontroller.

The ISS orbits the Earth every 90 minutes and NO-44 is in a polar orbit, so unless your balloon is really moving, it should be in a position to be heard by one or the other several times during the trip over the Atlantic.

At that height I would think your chances of being picked up by a satellite would be much higher than a ground station. It would be an interesting experiment to see if using satellite APRS exclusively would work, but I'm sure you'd rather see reliability over experimentation when it comes to telemetry.

How complex is your controller? I could see testing the balloon location against a boundary that could then switch in a different crystal in a radio something like this: http://tinyurl.com/bbzq4k3 (Google conversion of a Ramsey 2meter crystal controlled FM transmitter manual). There's not much available that would be simple enough to be switched unless your controller is fairly advanced. In fact the only small agile synthesized transceiver that can be remotely tuned "off the shelf" I can think of right now is the FT-817.

Maybe reach out to Byonics.com and see if they have any way of changing freq on their beacon radios. Don't forget that your TNC will also need to have a different path (ARISS) for the ISS and NO-44 to digipeat.

Want of a 64bit OS is why I switched to Linux a few years ago. I picked up a Core2 laptop and was disappointed to see Windows Vista Home was a 32bit OS. I just did it because I figured I paid for a 64 bit microprocessor, so why not use "the whole thing." Loaded up 64 bit Ubuntu and never looked back.

I should send Microsoft a note thanking them for being stingy with Windows. Up until that time I didn't have any beef against MS, and actually didn't think Vista was any better or worse than XP (although the actual delivered product was nothing at all like what was promised), but I couldn't figure out why they wanted to keep home users in the past. I guess it had more to do with maintaining compatibility with outdated hardware more than anything else.

While a bare driver will produce sound, I wouldn't call it a speaker. Drivers are designed to be put in an enclosure, usually just a simple air-tight box will suffice. The main reason is because the air in the enclosure acts like a spring or dampener for the driver's cone, making it much more efficient and also increasing the linearity of the frequency response.

You really don't need much of a box to make drivers work better either. An old Pringles' can might work for small drivers, a disposable plastic container, just about anything that can be sealed tight will work.

Another good program for tracking is Gnome Predict. It's open source and has a lot of options for controlling both radios and rotators. It was designed for Linux, but has been ported to Windows and MacOS. It might be a little more difficult to get working than SatPC (I haven't tried SatPC, so I can't compare), but it's free to try and I've had good results.

http://gpredict.oz9aec.net/

I'm in the process of upgrading the RF side of my setup so hopefully I'll get some good contacts soon. When my Earthstation gets a little more reliable I'll put up some more videos of my (somewhat) inexpensive setup using a telescope mount.

I have a Diamond SX40C Power/SWR meter. It's range is 144-470MHz, according to the label on the bottom. For Yagi antennas like yours you should have no problem reading reasonably accurate SWR using it. However if you try to use it with a "rubber duck" style antenna you likely won't get a real number, mostly due to the fact that radio-mounted antennas depend on your arm as a ground plane, unless you add a "tiger tail" counterpoise (or install a 1/2 wave antenna). I guess if you put an SMA panel mount on an aluminum plate and attached some ground wires you could get a true reading, but might be more trouble than it's worth.

But most HTs can handle a wide range of reflections without having any problems. Many all mode radios like the FT897 and FT817 have built in SWR meters, but also won't tolerate a poor antenna match.

It's also useful for sending status updates, like "watching TV" or "checking into the 40 meter net."