Like to track balloons? How about tracking radiosondes!


Mark Conner N9XTN
 

GPSLers,

Mike KD2EAT and I did a presentation a couple of years ago about tracking NWS radiosondes.  At that time, the "price of entry" was a little steep both in terms of Raspberry Pi setup and building a 1680 MHz helical antenna with an attached LNA.  

Since then, more and more of the NWS sites have migrated to 400 MHz for their sondes.  In addition, some sites use Graw and Vaisala sondes which have meteorological data that is decodeable by the Pi software.  The Lockheed Martin LMS-6 series only has lat/lon/alt data that is decodeable.  The user community reports very good 400 MHz range performance (200 mi/300 km or more if sonde is above horizon) using simple antennas (1/4 ground plane) and no preamp necessary most of the time.

If you are near a site that launches 400 MHz sondes, you can get into the tracking business with these items:
  • 403 MHz ground plane antenna (maybe $5 for a SO-239 or N bulkhead connector and some solid 12-14 ga copper wire)
  • Feedline with appropriate ends ($20-ish depending on length needed)
  • RTL-based SDR covering 400 MHz band (most of them, $20-30, Nooelec is a good brand)
  • Raspberry Pi 3B or 4 (Zero will probably not give good enough performance)
For 1680 MHz tracking, you'd need these items:
  • 1680 MHz helical antenna (3D-printer file available)
  • 1680 MHz LNA ($50)
  • Bias-T capability on the SDR to power the LNA via feedline
A note about Raspberry Pi's - they seem to be in short supply at the moment.  Pricing on Amazon is kind of high right now IMO and availability is not so great.  There appear to be plenty of 4 Gb Pi 4's available, but they're expensive and 4 Gb RAM is overkill for this application.  Pi 3's are priced well above the normal MSRP of ~$35, even allowing for typical kit parts.  More extensive searching might be worth some time.

The Linux "radiosonde_auto_rx" software is now installable within a Docker container.  You do not need in-depth knowledge of Docker to install the software, and Docker manages all the library dependencies for you.  Software updates are really simple and Mark VK5QI is very active in maintaining and upgrading this software.

https://github.com/projecthorus/radiosonde_auto_rx/wiki has all the info about how the receiver software works and how to install it.  The instructions are very clear and the user community is pretty helpful.  radiosonde_auto_rx@... is the email list.  

sondehub.org is a central location for tracking radiosondes.  You can see where current stations are receiving data (green circles) and where sondes are launched (gray).  When there are sonde flights in progress, you will also see their tracks on the site.  Clicking on a circle brings up info about the type, timing, and frequency of sondes being launched.  If the sonde site reports the sonde type is RSxx, LMS-6 403, or DFM-XX, you can receive it on a 400 MHz antenna.  This site is global in nature, with quite a few European, US, and Australian users but only a handful of Canadians appearing.  

My own station is a 1680 MHz setup that has been in operation since April 2020 - at first, just a portable setup but now a weatherproof one outside on a mast.  The local NWS office will migrate to 400 MHz next spring, so I need to get busy and build an antenna for it.  

This might make a good winter project if the weather is too unfavorable for doing ARHAB launches and chases in your area.  Sorry if this seems a little random, but I'm hoping more people in our community will give this a try. 

73 de Mark N9XTN


Christopher Rose
 

Vilros.com for Pis

-----------------------------------------

From: "Mark Conner N9XTN"
To: GPSL@groups.io
Cc:
Sent: Wednesday November 24 2021 4:41:46PM
Subject: [GPSL] Like to track balloons? How about tracking radiosondes!

GPSLers,

Mike KD2EAT and I did a presentation a couple of years ago about tracking NWS radiosondes.  At that time, the "price of entry" was a little steep both in terms of Raspberry Pi setup and building a 1680 MHz helical antenna with an attached LNA.  

Since then, more and more of the NWS sites have migrated to 400 MHz for their sondes.  In addition, some sites use Graw and Vaisala sondes which have meteorological data that is decodeable by the Pi software.  The Lockheed Martin LMS-6 series only has lat/lon/alt data that is decodeable.  The user community reports very good 400 MHz range performance (200 mi/300 km or more if sonde is above horizon) using simple antennas (1/4 ground plane) and no preamp necessary most of the time.

If you are near a site that launches 400 MHz sondes, you can get into the tracking business with these items:
  • 403 MHz ground plane antenna (maybe $5 for a SO-239 or N bulkhead connector and some solid 12-14 ga copper wire)
  • Feedline with appropriate ends ($20-ish depending on length needed)
  • RTL-based SDR covering 400 MHz band (most of them, $20-30, Nooelec is a good brand)
  • Raspberry Pi 3B or 4 (Zero will probably not give good enough performance)
For 1680 MHz tracking, you'd need these items:
  • 1680 MHz helical antenna (3D-printer file available)
  • 1680 MHz LNA ($50)
  • Bias-T capability on the SDR to power the LNA via feedline
A note about Raspberry Pi's - they seem to be in short supply at the moment.  Pricing on Amazon is kind of high right now IMO and availability is not so great.  There appear to be plenty of 4 Gb Pi 4's available, but they're expensive and 4 Gb RAM is overkill for this application.  Pi 3's are priced well above the normal MSRP of ~$35, even allowing for typical kit parts.  More extensive searching might be worth some time.

The Linux "radiosonde_auto_rx" software is now installable within a Docker container.  You do not need in-depth knowledge of Docker to install the software, and Docker manages all the library dependencies for you.  Software updates are really simple and Mark VK5QI is very active in maintaining and upgrading this software.

https://github.com/projecthorus/radiosonde_auto_rx/wiki has all the info about how the receiver software works and how to install it.  The instructions are very clear and the user community is pretty helpful.  radiosonde_auto_rx@... is the email list.  

sondehub.org is a central location for tracking radiosondes.  You can see where current stations are receiving data (green circles) and where sondes are launched (gray).  When there are sonde flights in progress, you will also see their tracks on the site.  Clicking on a circle brings up info about the type, timing, and frequency of sondes being launched.  If the sonde site reports the sonde type is RSxx, LMS-6 403, or DFM-XX, you can receive it on a 400 MHz antenna.  This site is global in nature, with quite a few European, US, and Australian users but only a handful of Canadians appearing.  

My own station is a 1680 MHz setup that has been in operation since April 2020 - at first, just a portable setup but now a weatherproof one outside on a mast.  The local NWS office will migrate to 400 MHz next spring, so I need to get busy and build an antenna for it.  

This might make a good winter project if the weather is too unfavorable for doing ARHAB launches and chases in your area.  Sorry if this seems a little random, but I'm hoping more people in our community will give this a try. 

73 de Mark N9XTN


Barry L. Lankford
 

(See the last paragraph for my experience with obtaining Raspberry Pis recently)

As for chasing radiosondes: Been there, done that! And yeah, it was a lot of fun. I think I started chasing ozonesondes around 2006 with Bill Brown WB8ELK and Gary Dion N4TXI. University of Alabama-Huntsville's (UAH) Atmospheric Science department was launching Ozonesondes every Saturday at 1:00pm. Around that same time, I believe, Joe Leggio WB2HOL put up his steel tape measure & PVC pipe Yagi antenna design on a website. It was a simple 3-element Yagi for 2 meters that had a nice cardiod pattern with a deep & narrow notch on the backside, a broad forward beamwidth, and even some gain. Don't recall the year, but it was near June I think. I recall going to Sears (R.I.P.) and getting a nice discount on 1 inch tape measure refills because they were having a Father's Day sale! Nowadays, in the US, you could get 25 foot x 1 inch tapes for free from Harbor Freight!

The narrow notch was good for refining the direction. There's still a current website that has what appears to be the original WB2HOL design, although I think some of the links may be dead, particularly the ones for the YAGI-CAD41 program:

http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm
I was able to find the Zip file for Yagi-Cad on one of my old hard drives, but I recall that the program had some issues even then with the then-current version of MS-DOS (Yes, that's right, YagiCad runs in MS-DOS, NOT Windows!). I wouldn't even think about trying to run it with Win10's DOS window!

I have an Icom IC-R3 that works well at 403 MHz that I used in the "twenty-aughts" (or is it: "Twenty-naughties") with its extensible whip antenna, so I used YagiCad to re-tune WB2HOL's 2 Meter Yagi design to 403 MHz. Worked very well to replace the R3's whip -- I was able to pick up signals and direction from at least a mile away with the 'sonde laying on the ground in a tightly packed old residential area of a nearby city. No one else was able to get a signal at all, IIRC. When the balloon was a ways into the sky, I could pick it up from many miles away.

I also built a Tape Measure Yagi from WB2HOL's original 2 Meter dimensions. Never used it much, but it seemed to work well to add some extra range to 2M HT comms.

For both antennas, I didn't much like Joe's mechanical design, with its big worm-drive hose clamps and everything on the outside of the pipe, so I came up with my own design as you can see in the attached photos. I modified a spade-type 7/8th inch wood bit by grinding off equal amounts from each edge so it'd drill a 0.807" hole (I think that was the dimension - it's the outside diameter of 1/2 inch pipe). I used the modified bit to remove the shoulders inside the tee and cross fittings for the elements, so the tape would lay all the way through the fitting without kinking. The elements were clamped in place with 3/4" plugs which were longitudinally slit (band-saw kerf) and filled with RTV. I actually used Google/Trimble's "SketchUp" 3D modelling software to draw detailed plans of how to make all the PVC parts and assemble them with the tape measure elements, unfortunately I can't find the files now. The hairpin match was also moved inside the PVC parts. I had no problems at all soldering to the steel tape, but I used a single-cut mill bastard file to file off the paint AND the dull coating on the steel, until I got bright, shiny metal. It would've been easy to use RTV instead of PVC cement to assemble the antennas and make them watertight, and probably capable to being disassembled for repair if necessary.

As for the Raspberry Pis, I just ordered and received a 4GB R-Pi 4B, a 8GB R-Pi 4B, an R-Pi Zero 2 W and an R-Pi Pico (along with a lot of other goodies) from The US Raspberry Pi Shop (Pishop.us) almost a month ago. The parts were priced the same as the Foundation's advertised prices (but shipping was extra). I got everything I ordered, but there were a few things I wanted that were out of stock.

Barry N4MSJ


On 11/24/2021 2:00 PM, Mark Conner N9XTN wrote:
GPSLers,
Mike KD2EAT and I did a presentation a couple of years ago about tracking NWS radiosondes.  At that time, the "price of entry" was a little steep both in terms of Raspberry Pi setup and building a 1680 MHz helical antenna with an attached LNA.
Since then, more and more of the NWS sites have migrated to 400 MHz for their sondes.  In addition, some sites use Graw and Vaisala sondes which have meteorological data that is decodeable by the Pi software.  The Lockheed Martin LMS-6 series only has lat/lon/alt data that is decodeable.  The user community reports very good 400 MHz range performance (200 mi/300 km or more if sonde is above horizon) using simple antennas (1/4 ground plane) and no preamp necessary most of the time.
If you are near a site that launches 400 MHz sondes, you can get into the tracking business with these items:
* 403 MHz ground plane antenna (maybe $5 for a SO-239 or N bulkhead
connector and some solid 12-14 ga copper wire)
* Feedline with appropriate ends ($20-ish depending on length needed)
* RTL-based SDR covering 400 MHz band (most of them, $20-30, Nooelec
is a good brand)
* Raspberry Pi 3B or 4 (Zero will probably not give good enough
performance)
For 1680 MHz tracking, you'd need these items:
* 1680 MHz helical antenna (3D-printer file available)
* 1680 MHz LNA ($50)
* Bias-T capability on the SDR to power the LNA via feedline
A note about Raspberry Pi's - they seem to be in short supply at the moment.  Pricing on Amazon is kind of high right now IMO and availability is not so great.  There appear to be plenty of 4 Gb Pi 4's available, but they're expensive and 4 Gb RAM is overkill for this application.  Pi 3's are priced well above the normal MSRP of ~$35, even allowing for typical kit parts.  More extensive searching might be worth some time.
The Linux "radiosonde_auto_rx" software is now installable within a Docker container.  You do not need in-depth knowledge of Docker to install the software, and Docker manages all the library dependencies for you.  Software updates are really simple and Mark VK5QI is very active in maintaining and upgrading this software.
https://github.com/projecthorus/radiosonde_auto_rx/wiki has all the info about how the receiver software works and how to install it.  The instructions are very clear and the user community is pretty helpful. radiosonde_auto_rx@googlegroups.com <mailto:radiosonde_auto_rx@googlegroups.com> is the email list.
sondehub.org <http://sondehub.org> is a central location for tracking radiosondes.  You can see where current stations are receiving data (green circles) and where sondes are launched (gray).  When there are sonde flights in progress, you will also see their tracks on the site. Clicking on a circle brings up info about the type, timing, and frequency of sondes being launched.  If the sonde site reports the sonde type is RSxx, LMS-6 403, or DFM-XX, you can receive it on a 400 MHz antenna.  This site is global in nature, with quite a few European, US, and Australian users but only a handful of Canadians appearing.
My own station is a 1680 MHz setup that has been in operation since April 2020 - at first, just a portable setup but now a weatherproof one outside on a mast.  The local NWS office will migrate to 400 MHz next spring, so I need to get busy and build an antenna for it.
This might make a good winter project if the weather is too unfavorable for doing ARHAB launches and chases in your area.  Sorry if this seems a little random, but I'm hoping more people in our community will give this a try.
73 de Mark N9XTN
_._,_._,_


Hank Riley
 

What a kick this is.  There are many newer (presumably better) versions of this original Yagi Cad 4.1 program from the author Paul of Australia.  They're ALL there including the very first version, 4.2, done in Quick Basic.  

Read the history to find out how the name 4.1 came about (it wasn't from Paul!) and other interesting tidbits, especially to the software writers on the GPSL list.


_______________________________________________________________

On Wednesday, November 24, 2021, 08:03:51 PM EST, Barry L. Lankford wrote:

 There's still a current website that has what appears to be the original WB2HOL design,
although I think some of the links may be dead, particularly the onesfor the YAGI-CAD41 program:

> http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm

I was able to find the Zip file for Yagi-Cad on one of my old hard
drives, but I recall that the program had some issues even then with the
then-current version of MS-DOS (Yes, that's right, YagiCad runs in
MS-DOS, NOT Windows!).  I wouldn't even think about trying to run it
with Win10's DOS window!


Garrett, Mark
 

Most of the sondes launched from Davenport do not fly due south but the ones that do I make an effort if they land in my zone.  I use simple tools to track and recover.  Over the attempts I have gone out on, I have recovered two of them.  Both launched in the morning. 
One of my goals would be to set up a fixed station that can receive and put the data out on APRS.FI  I do not have a Pi but some old 32 bit computers that can be loaded up with linux.  I believe the dongle I have is the favored one.  I have the antenna but I have very limited experience in Linus and would need assistance in getting it going. 

The nice thing about chasing is that it is a fun activity and  my enthusiasm has moved others to join the hunts.  It is a resource that hones our skills.

Mark 

On Wed, Nov 24, 2021 at 2:00 PM Mark Conner N9XTN <mconner1@...> wrote:
GPSLers,

Mike KD2EAT and I did a presentation a couple of years ago about tracking NWS radiosondes.  At that time, the "price of entry" was a little steep both in terms of Raspberry Pi setup and building a 1680 MHz helical antenna with an attached LNA.  

Since then, more and more of the NWS sites have migrated to 400 MHz for their sondes.  In addition, some sites use Graw and Vaisala sondes which have meteorological data that is decodeable by the Pi software.  The Lockheed Martin LMS-6 series only has lat/lon/alt data that is decodeable.  The user community reports very good 400 MHz range performance (200 mi/300 km or more if sonde is above horizon) using simple antennas (1/4 ground plane) and no preamp necessary most of the time.

If you are near a site that launches 400 MHz sondes, you can get into the tracking business with these items:
  • 403 MHz ground plane antenna (maybe $5 for a SO-239 or N bulkhead connector and some solid 12-14 ga copper wire)
  • Feedline with appropriate ends ($20-ish depending on length needed)
  • RTL-based SDR covering 400 MHz band (most of them, $20-30, Nooelec is a good brand)
  • Raspberry Pi 3B or 4 (Zero will probably not give good enough performance)
For 1680 MHz tracking, you'd need these items:
  • 1680 MHz helical antenna (3D-printer file available)
  • 1680 MHz LNA ($50)
  • Bias-T capability on the SDR to power the LNA via feedline
A note about Raspberry Pi's - they seem to be in short supply at the moment.  Pricing on Amazon is kind of high right now IMO and availability is not so great.  There appear to be plenty of 4 Gb Pi 4's available, but they're expensive and 4 Gb RAM is overkill for this application.  Pi 3's are priced well above the normal MSRP of ~$35, even allowing for typical kit parts.  More extensive searching might be worth some time.

The Linux "radiosonde_auto_rx" software is now installable within a Docker container.  You do not need in-depth knowledge of Docker to install the software, and Docker manages all the library dependencies for you.  Software updates are really simple and Mark VK5QI is very active in maintaining and upgrading this software.

https://github.com/projecthorus/radiosonde_auto_rx/wiki has all the info about how the receiver software works and how to install it.  The instructions are very clear and the user community is pretty helpful.  radiosonde_auto_rx@... is the email list.  

sondehub.org is a central location for tracking radiosondes.  You can see where current stations are receiving data (green circles) and where sondes are launched (gray).  When there are sonde flights in progress, you will also see their tracks on the site.  Clicking on a circle brings up info about the type, timing, and frequency of sondes being launched.  If the sonde site reports the sonde type is RSxx, LMS-6 403, or DFM-XX, you can receive it on a 400 MHz antenna.  This site is global in nature, with quite a few European, US, and Australian users but only a handful of Canadians appearing.  

My own station is a 1680 MHz setup that has been in operation since April 2020 - at first, just a portable setup but now a weatherproof one outside on a mast.  The local NWS office will migrate to 400 MHz next spring, so I need to get busy and build an antenna for it.  

This might make a good winter project if the weather is too unfavorable for doing ARHAB launches and chases in your area.  Sorry if this seems a little random, but I'm hoping more people in our community will give this a try. 

73 de Mark N9XTN



--
Mark Garrett
KA9SZX



Mark Conner N9XTN
 

Hi Mark,

An older PC with Linux should be fine.  I'm used to Raspbian (Debian) but I think most any flavor will work - Docker should abstract the Linux distro away from the user.  The instructions on Github should be applicable for PC installs. NWS Quad Cities is using 400 MHz.  

Radiosonde_auto_rx can also be configured to send objects to APRS-IS to share sonde tracks with APRS users.

I've found that the 3-turn helical is not so directional that for mobile tracking you have to do a lot of repointing.  If you're within ~20 miles of the sonde, pointing straight-ish up works well enough.

Once Omaha/Valley goes to 400 MHz, I think I'll be able to chase with a dual-band mobile well enough.  My current solution for 1680 MHz involves pointing the helical out the sunroof.

73 de Mark N9XTN

On Wed, Nov 24, 2021 at 10:14 PM Garrett, Mark <ma-garrett@...> wrote:
Most of the sondes launched from Davenport do not fly due south but the ones that do I make an effort if they land in my zone.  I use simple tools to track and recover.  Over the attempts I have gone out on, I have recovered two of them.  Both launched in the morning. 
One of my goals would be to set up a fixed station that can receive and put the data out on APRS.FI  I do not have a Pi but some old 32 bit computers that can be loaded up with linux.  I believe the dongle I have is the favored one.  I have the antenna but I have very limited experience in Linus and would need assistance in getting it going. 

The nice thing about chasing is that it is a fun activity and  my enthusiasm has moved others to join the hunts.  It is a resource that hones our skills.

Mark 

On Wed, Nov 24, 2021 at 2:00 PM Mark Conner N9XTN <mconner1@...> wrote:
GPSLers,

Mike KD2EAT and I did a presentation a couple of years ago about tracking NWS radiosondes.  At that time, the "price of entry" was a little steep both in terms of Raspberry Pi setup and building a 1680 MHz helical antenna with an attached LNA.  

Since then, more and more of the NWS sites have migrated to 400 MHz for their sondes.  In addition, some sites use Graw and Vaisala sondes which have meteorological data that is decodeable by the Pi software.  The Lockheed Martin LMS-6 series only has lat/lon/alt data that is decodeable.  The user community reports very good 400 MHz range performance (200 mi/300 km or more if sonde is above horizon) using simple antennas (1/4 ground plane) and no preamp necessary most of the time.

If you are near a site that launches 400 MHz sondes, you can get into the tracking business with these items:
  • 403 MHz ground plane antenna (maybe $5 for a SO-239 or N bulkhead connector and some solid 12-14 ga copper wire)
  • Feedline with appropriate ends ($20-ish depending on length needed)
  • RTL-based SDR covering 400 MHz band (most of them, $20-30, Nooelec is a good brand)
  • Raspberry Pi 3B or 4 (Zero will probably not give good enough performance)
For 1680 MHz tracking, you'd need these items:
  • 1680 MHz helical antenna (3D-printer file available)
  • 1680 MHz LNA ($50)
  • Bias-T capability on the SDR to power the LNA via feedline
A note about Raspberry Pi's - they seem to be in short supply at the moment.  Pricing on Amazon is kind of high right now IMO and availability is not so great.  There appear to be plenty of 4 Gb Pi 4's available, but they're expensive and 4 Gb RAM is overkill for this application.  Pi 3's are priced well above the normal MSRP of ~$35, even allowing for typical kit parts.  More extensive searching might be worth some time.

The Linux "radiosonde_auto_rx" software is now installable within a Docker container.  You do not need in-depth knowledge of Docker to install the software, and Docker manages all the library dependencies for you.  Software updates are really simple and Mark VK5QI is very active in maintaining and upgrading this software.

https://github.com/projecthorus/radiosonde_auto_rx/wiki has all the info about how the receiver software works and how to install it.  The instructions are very clear and the user community is pretty helpful.  radiosonde_auto_rx@... is the email list.  

sondehub.org is a central location for tracking radiosondes.  You can see where current stations are receiving data (green circles) and where sondes are launched (gray).  When there are sonde flights in progress, you will also see their tracks on the site.  Clicking on a circle brings up info about the type, timing, and frequency of sondes being launched.  If the sonde site reports the sonde type is RSxx, LMS-6 403, or DFM-XX, you can receive it on a 400 MHz antenna.  This site is global in nature, with quite a few European, US, and Australian users but only a handful of Canadians appearing.  

My own station is a 1680 MHz setup that has been in operation since April 2020 - at first, just a portable setup but now a weatherproof one outside on a mast.  The local NWS office will migrate to 400 MHz next spring, so I need to get busy and build an antenna for it.  

This might make a good winter project if the weather is too unfavorable for doing ARHAB launches and chases in your area.  Sorry if this seems a little random, but I'm hoping more people in our community will give this a try. 

73 de Mark N9XTN



--
Mark Garrett
KA9SZX



Virus-free. www.avg.com


James Ewen VE6SRV
 

Back in my day, you had to lay on the lawn with your yagi sweeping the sky for the signal, and then use RDF techniques to chase down the payload. (Do I sound like one of those old timer ham radio guys yet?)

Before the turn of the century, I got it into my head that chasing balloons would be fun. I just happen to live 60 km due east of the local weather station WHK. Prevailing winds tend to put the flight path right overhead. We went for a tour and watched the meteorologist fill and launch a radiosonde. Then I started tracking the 400 MHz payloads using my IC-24AT and a UHF yagi antenna. I would lay on the lawn sweeping the yagi around looking for the signal. I had just moved into town and the neighbors didn't really know what to think of the nutty neighbor laying on the lawn with a tiny goofy looking ladder in his hands. The curious ones would get to stare into the blue sky and if they were lucky enough to have good eyesight, they would see the balloon flying overhead.

I soon learnt just where I would like to see the balloon burst in order to determine whether I wanted to go chase down the payload or not. Based on where the balloon was visually observed to burst, I would have a rough idea of where I needed to head to intercept the payload. Years later as the prediction software got better, we were able to determine where to head before launch, but I could still get a rough idea of where to head if I could observe the burst. Even if telemetry failed, we could get close enough to track down the RF signals.

Decoding GPS signals from the radiosondes makes it like shooting fish in a barrel! I might have to hook my SDR up to one of my old Pi3s and see what I can decode. Then I might have to go collect a bunch of radiosondes...

James
VE6SRV


Barry L. Lankford
 

On 11/24/2021 8:08 PM, Hank Riley via groups.io wrote:
What a kick this is.  There are many newer (presumably better) versions of this original Yagi Cad 4.1 program from the author Paul of Australia.  They're ALL there including the very first version, *4.2*, done in Quick Basic.
Read the history to find out how the */name/* 4.1 came about (it wasn't from Paul!) and other interesting tidbits, especially to the software writers on the GPSL list.
http://www.yagicad.com/yagicad/YagiCAD.htm
Hank,

I agree, and thanks for that link. At my age, and while I was composing my previous email in this thread, it occurred to me that I ought to do a search for YagiCad's author by his name, but by the time I finished the email, that thought had evaporated from my mind. I've bookmarked the link, and color-tagged your email.

I may never get around to making another tape measure Yagi, but I'll enjoy reading (and thinking) about the kinds of antennas that could be made that way.

I've been wondering if some similar techniques could be used to make a PVC and tape measure LOG PERIODIC DIPOLE ARRAY! I've also been thinking about an easy way to make DIY radomes for antenna ideas that might be hard to weather-proof, such as Kent Britain's (WA5VJB) PCB LPDA antennas.

I hope I can eventually locate my old CAD drawings for the way I modified the PVC backbone of my antennas. With a little strategically placed RTV, they could probably be made to survive well outdoors. In the past, I kept my Icom IC-R3 plugged into a power adapter and turned ON continuously, with my 403 MHz antenna (all of this was indoors), pointed towards the university's launch site, so any time they launched a WX balloon, I got a quick warning (leave the R3's volume turned way up!).

By the way, in the photos with my previous email, attached to each antenna is a snap-on mast adapter made up of a modified PVC Tee, some tie-wraps, a couple of short lengths of 1/2" PVC pipe and a PVC 90 deg. elbow that allows me to orient the antenna on a 1/2" PVC pipe mast for either vertical or horizontal polarization. The PVC pipe mast was attached to a ceiling joist in the garage or one of the corner posts of a welded-wire shelving unit in a storage bedroom. Very convenient. Oh, one other thing: the short PVC pipe pieces and 90 deg. elbow were only used when the antenna also needed an "elevation" setting (other than horizontal). I used that capability for satellites a few times.

Raspberry Pis, APRS and SDR software, and DVB-T dongles weren't "a thing" back then, just 15 to 20 years ago, but now it's so easy to put a tracking symbol up on APRS maps like aprs.fi, when a WX balloon launch is detected. Those fairly recently available things lead to even more ideas:

For example, A Raspberry Pi HQ camera coupled with a C-mount to T-mount adapter to an inexpensive and very common, 135mm telephoto lens (left over from your old 35mm film SLR) gives you a 17X telephoto Hi-Def IP streaming video camera, a near ideal optical power for seeing HABs at altitude. With some easily available hardware from the DIY 3D printer market, and some high school solid geometry (I've done that), you could have an auto-tracking video camera tracking and streaming live video of any passing HABs and radiosonde balloons. What a science-fair project that would be for some high school kid!

Barry
N4MSJ

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On Wednesday, November 24, 2021, 08:03:51 PM EST, Barry L. Lankford wrote:
 There's still a current website that has what appears to be the original WB2HOL design,
although I think some of the links may be dead, particularly the onesfor the YAGI-CAD41 program:

> http://theleggios.net/wb2hol/projects/rdf/tape_bm.htm
I was able to find the Zip file for Yagi-Cad on one of my old hard
drives, but I recall that the program had some issues even then with the
then-current version of MS-DOS (Yes, that's right, YagiCad runs in
MS-DOS, NOT Windows!).  I wouldn't even think about trying to run it
with Win10's DOS window!
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