Re: Like to track balloons? How about tracking radiosondes!
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.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!