My take on the WB2HOL tape measure Yagi

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K7XRL

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So I want to work some satellites with my handheld radio, and I couldn't hear any of the packets from the ISS using a Nagoya whip on the radio, a 1/4 wave ground plane, a magnet mount mobile antenna, or a TV twin lead slim jim. granted, the passes were not optimal. But I have been wanting to try this antenna for a while so I finally got the parts yesterday and built one.

Here is the link I used for the instructions:

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

All of the element lengths and spacing are taken right from these plans, along with the length of the wire used for the hairpin match.

The plans call for attaching all of the elements using stainless hose clamps, but the author does mention that he would use screws to attach the director and reflector to reduce weight and bulk. He also states that the screws would weaken the tape. Additionally, he mentions some builders using rubber washers as spacers to help the tape match the radius of the pipe fittings.

I decided to use some industrial strength Velcro to mount the director and reflector elements, and reinforce the joints with nylon zip ties. This seems to work well, and doesn't weaken the tape by putting holes in it. It also has the added benefit of making a better match to the radius of the pipe, similar to the washers described in the original article.

I then went one step further and added velcro bits to hold the elements in a folded configuration for easier storage and transport. I have seen some guys roll them up individually but that seems to be too fiddly and time consuming. folding the elements and detaching the director makes the whole thing collapse down to a very reasonable size.

To mount it I used a CB antenna mirror mount that I drilled and tapped with 1/4-20 threads to mate with a standard camera tripod. It is light enough not to tip over, and this tripod has a hook for hanging a sandbag to add weight if needed. If the antenna needs to be stiffened up for windy conditions, you could just stick some PVC into the sides of the fittings and tape the elements down (or use more velcro).

The hardest part of the whole operation was holding solder, soldering iron, hairpin match, and cable all at once. My 'helping hands" were not enough. Just as was advised in the article, I tinned everything first. However, the article advises against soldering everything in place because it could melt the PVC fittings. I found that slipping a scrap piece of tape measure under the piece being soldered, and loosely clamping them both onto the fitting allowed me to solder the connections in place without melting the pipe, though the insulation on the hairpin took a beating.

I will probably eventually get a 1"-3/4" reducer and an end cap and mount an SO239 in the end and route the cable through the inside of the mast. I also want to get some plasti-dip for the ends of the elements. For now I used electrical tape covered with heat shrink but the dip would be a more streamlined solution. I looked 4 places and nobody stocked it.

The match is not perfect but it is good enough to satisfy me. It is under 2:1 SWR from 144.000 to 148.000 MHz, and under 1.2:1 at 145.825 as verified with an MFJ-259C.

Here are a few pics. It is my first scratch built Yagi so go easy on me! :D

Fully deployed:
IMG_20150228_173116.jpg


Elements folded:
IMG_20150228_173245.jpg


Detail of director mounting with Velcro and zip ties:
IMG_20150228_173024.jpg


Connections and hairpin match:
IMG_20150228_173142.jpg


Velcro tabs to fold elements:
IMG_20150228_173213.jpg


Detail of mount:
IMG_20150228_173053.jpg


End protection:
IMG_20150228_173127.jpg



Thanks for looking!
 

K7XRL

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Not yet. :D

My tracking app didn't show any passes at my location yet since I finished the antenna. There are a few pcsat passes but I read that one only works during daylight.

OK, I guess the app was configured to display only visible passes, so I might have more opportunities than I thought.
 
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vagrant

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Looks good! These tape measure Yagi's are an inexpensive solution for satellite contact and transmitter hunts.
 

K7XRL

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Tried ISS today but no luck. I later read that they have some EVA's planned for March 1 and the radios would be off. issfanclub.com reports no signal for the last 10 hours or so either.
 

K7XRL

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Ok, just to give an anecdotal report on the performance, I had two ISS passes today, one at 29 and one at 30 degrees. On both passes I used Doppler correction, and I heard strong clear packets. On the first pass I turned the antenna in the direction where the station was supposed to "set" and for 18 seconds after my tracking app indicated the station had passed the horizon, I was still receiving packets.

I am satisfied the antenna works well for reception!
 

K7XRL

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Sweet ! I need to get off my bum and have a go at the ISS

Do it!

There are plenty of tracking apps out there. My current favorite is ISS tracker for android. It has a nice compass feature that shows you a graphical representation of the passes in real time, along with elevation and azimuth. It also tracks other amateur satellites as well as iridium flares, comets, planets and a few other things. The only thing I don't like about it is the frequencies listed for the ham sats look like the developer just took them from a chart of Doppler corrected uplink frequencies. So they don't give downlink in most cases, and they also don't give the correct center frequency. I emailed the Dev about this issue for pcsat and he fixed it's but that was just the one satellite. The rest need correction too, but I don't have the time to look them all up.

It would be awesome if he would add real time Doppler correction to the display but that would likely be a lot of work.

Anyhow give it a shot. I just sent my QSL request in the mail today. Now begins the long wait. :D
 

KE5MC

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Nice Build! I had not thought of using velcro attached directly to the tape. I use a velcro cable tie loop adjusted to fit over the folded elements.

Attached are my changes to allow the tape to lay flat across the tee or cross piece. I notch out the plastic to make a cylinder out of the area where the tape lays. Not perfect as a molded part like that has cast to allow part to pop out of mold.

Used Sharpe to center mark tape and PVC for adjustments when deployed. Used TieRaps to hold in position. Used RG174 and choke at the feed point. Used it for foxhunt with great success and should try the ISS, but have not.

With the broad forward gain at the 3db points it should make pointing in the direction of the satellite less critical. For fox hunting the deep narrow notch in the back of the antenna is the important design objective the designer was looking for.

Mike
 
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K7XRL

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Cool! it is nice to see other ways to construct these. Makes for a better eventual version 2. :D
 

KG6ABF

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So I want to work some satellites with my handheld radio, and I couldn't hear any of the packets from the ISS using a Nagoya whip on the radio, a 1/4 wave ground plane, a magnet mount mobile antenna, or a TV twin lead slim jim. granted, the passes were not optimal. But I have been wanting to try this antenna for a while so I finally got the parts yesterday and built one.

{snip}

Thanks for looking!

Are you using it in both yagi AND as what appears to be a folded or possibly some sort of quad configuration?

I know a few folks seriously into sat work and they like circular polarized antennas. QST had an article about the "Egg-Beater" antenna and plans to build it. I built some Quagis for some hams and they use it with their HTs.
I have rigs that will do Sat work and years ago I made a number of arrays. Home-brewed the Quagis, made the frames and then rigged up an adjustable elevation mount. I did the ARM STRONG" rotor method at first but when I went to a 4 bay and alter 8 bay I went to a rotor. If you get seriously into it you might consider an AZ-EL rotor to handle the elevation and rotation to make the changes easier on you.

I know some who got a used Dish or Direct TV dish and modded those into antennas. I don't have plans for them but you could do a search. the distances for the directors and driven element get much more critical the higher in frequency you go so using a millimeter or more precise measuring device is best to make sure you get it as close as you can. I know the Quaqis I built using welding rod, some stiff #4 wire and PVC or wood( hey it was what the guy wanted) worked well and very lightweight. You can make a 8-9 element using a 10 foot section of 1 inch PVC welding rod a few PVC connectors/adapters and it is very cost effective.

The gain and F/B figures are good. Forward gain is about 12 dB or more depending on boom length F/B is at least 20dB or more and the side rejection is acceptable.

Just search out Quagi 2 meters or 440 (70CM) you will find lots of plans. Try to make one larger than 4 elements as the pattern tightens up, gain is increased and it is still very cheap but sturdy when you finish. The added bonus is you get an antenna that is actually fairly portable. I used a Tee mount and cut the boom in half. I could quickly go from Vertical to Horizontal with a simple twist of the front and back sections.

Although slightly less useable for straight sat work is the MOXON, easy to build very sturdy. basically 2 dipoles a frame some insulators wire, copper tubing PVC can be used. and could be used possibly but might be better suited for repeater, simplex and SSB DX work.

Hope that helps you out somewhat.
 
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K7XRL

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Nov 26, 2014
Messages
97
Are you using it in both yagi AND as what appears to be a folded or possibly some sort of quad configuration?

I know a few folks seriously into sat work and they like circular polarized antennas. QST had an article about the "Egg-Beater" antenna and plans to build it. I built some Quagis for some hams and they use it with their HTs.
I have rigs that will do Sat work and years ago I made a number of arrays. Home-brewed the Quagis, made the frames and then rigged up an adjustable elevation mount. I did the ARM STRONG" rotor method at first but when I went to a 4 bay and alter 8 bay I went to a rotor. If you get seriously into it you might consider an AZ-EL rotor to handle the elevation and rotation to make the changes easier on you.

I know some who got a used Dish or Direct TV dish and modded those into antennas. I don't have plans for them but you could do a search. the distances for the directors and driven element get much more critical the higher in frequency you go so using a millimeter or more precise measuring device is best to make sure you get it as close as you can. I know the Quaqis I built using welding rod, some stiff #4 wire and PVC or wood( hey it was what the guy wanted) worked well and very lightweight. You can make a 8-9 element using a 10 foot section of 1 inch PVC welding rod a few PVC connectors/adapters and it is very cost effective.

The gain and F/B figures are good. Forward gain is about 12 dB or more depending on boom length F/B is at least 20dB or more and the side rejection is acceptable.

Just search out Quagi 2 meters or 440 (70CM) you will find lots of plans. Try to make one larger than 4 elements as the pattern tightens up, gain is increased and it is still very cheap but sturdy when you finish. The added bonus is you get an antenna that is actually fairly portable. I used a Tee mount and cut the boom in half. I could quickly go from Vertical to Horizontal with a simple twist of the front and back sections.

Although slightly less useable for straight sat work is the MOXON, easy to build very sturdy. basically 2 dipoles a frame some insulators wire, copper tubing PVC can be used. and could be used possibly but might be better suited for repeater, simplex and SSB DX work.

Hope that helps you out somewhat.

No. I realize it looks like folded dipole elements or loop elements but that is just how it looks when I have the yagi elements folded for storage and transport. I have seen tape measure yagi builds where people roll up the elements and velcro around the outside, and that would make it even more compact. But I just wanted it to fold up enough to get it in and out of a car without hanging up on the door. :D

I left the junction between the front element and the rear two elements unglued so I can pull it apart and make it even more compact that way, if need be.
 

KG6ABF

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So California
No. I realize it looks like folded dipole elements or loop elements but that is just how it looks when I have the yagi elements folded for storage and transport. I have seen tape measure yagi builds where people roll up the elements and velcro around the outside, and that would make it even more compact. But I just wanted it to fold up enough to get it in and out of a car without hanging up on the door. :D

I left the junction between the front element and the rear two elements unglued so I can pull it apart and make it even more compact that way, if need be.

Ok it certainly would be more compact. If you do a search on this site:
VE2ZAZ - Arrow-Style VHF/UHF Portable Satellite Antenna

or this one:
http://www.arkansas-aresraces.org/HAMMAGS/e15.pdf

which is a PDF with color pics it might give some more ideas.
 

fteter

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May 29, 2015
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A Little Late

I'm a little late to this party, but thought I'd throw in my two cents.

First, thanks to K7XRL for sharing your take on the tape measure Yagi. Brilliant.

I just finished my own build earlier today, mostly following the techniques used here. One important change: while I love soldering, soldering does not love me. So I used RG58 with lugs and connected with self-taping screws as suggested in the link provided by K7XRL.

My SWR on 2 meters ranges between 1:1 and 1.2:1 across the band. 70cm ranges between 1.5:1 and 1.7:1. Really pleased with the 2m SWR and the 70cm is adequate.

In some preliminary field testing, I'm finding that direction separation is really good...strong signals in the direction pointed with essentially no competing signal interference from other directions. From my QTH, my signal range is about 10 miles further with the Yagi at 5 feet of height than with my Diamond X30a vertical that's about 20 feet high. But that could change in 10 minutes as conditions change. Good signal reports from local QSOs so far, but more testing on signal strength to come.

Overall, it's been a fun experiment with good results so far. Glad I came across this design and very grateful to K7XRL for sharing.
 
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