Recommendations: Dish antenna or yagi for pulsar detection ?

[Robert Hamers]

I've been working with my 1-meter horn antenna and getting good results with it. Now i"d like to move to something with higher sensitivity and better directionality.  I"m very interested in pulsars and hope to be able to detect them, and was inspired by Peter East's youtube video. 

My first thought was to go with a 1 or 2-meter dish antenna. I can get a 1.9 m dish from rfhamdesign, but it's really expensive, mostly because the shipping costs alone to US are almost 900 Euro/1000 USD (more than the cost of the antenna itself).   TechnicalAntennas has a 1-meter antenna kit that is affordable as an option, but being smaller I'm not sure it is is large enough to do what I want.  Or I can likely build something like Alex's Yagi design.  

I did try to make a 2-meter dish but decided that I don't have the facilities to do precision bending of aluminum to the required level.   But I have access to a machine shop and a lathe so should be able to make the disks and spacers for a Yagi.

Any thoughts appreciated !  (or reasonably-price options I haven't thought of..)

 

Bob 

[ja...@ganssle.com]

Bob,

 

I recently built a 1.5 meter dish using fiberglass and stainless steel mesh. I built a wooden form for 1/8^th of the dish, and laminated a layer of fiberglass cloth on it, followed by the mesh, followed by a layer of fiberglass mat. Those were vacuum bagged. Then I made ribs from ¼” Baltic Birch plywood, all attached to a wooden hub turned on the lathe. The 8 dish segments got fiberglassed together. Now I’m working on the feed. I’m pretty happy with it. Tests show a surface accuracy of about 2 to 3 mm. I spent a ton of time getting the wooden form nearly perfect.

 

To stiffen the sections I fiberglassed 5/8” tubing in three places on the back of each dish segment.

 

(Version 1 of the form was crushed in the vacuum bag!).

 

I didn’t track costs, but fiberglass resin is pretty cheap from Amazon as is the cloth and mat.

 

 

Jack

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[andrew....@googlemail.com]

Looks beautiful to me!

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[Robert Hamers]

Wow- that looks great!  I tried making a frame from 8 pieces of aluminum L, using a wooden frame much like yours, but the aluminum pieces weren't stiff enough to hold the shape.  Maybe I'll have to reconsider.... thanks for the info!

[Alex P]

Just a thought : With small diameter dishes, a  beam-narrowing Feed Choke Ring is a bit large.

It might be preferable to build a dish with an f/D ratio ~  0.27 - 0.30 to minimize spillover.

Alex

[Ayushman Tripathi]

Hi Robert,

Some options you might look at:

I bought this 2.4m dish for around $110 last year, now it seems to be 150 USD:

https://www.solid.sale/Solid-Dish-Antenna/C-Band-Dish-Antenna/8ft-Dish

I also found this 12ft one (~3.6m), around $500:

https://www.solid.sale/Solid-Dish-Antenna/C-Band-Dish-Antenna?product_id=53

It says out of stock and MOQ 1000, but you can try contacting the manufacturer directly they may ship manually. If you can't get it through the site, there are some B2B marketplace sites like https://www.indiamart.com/ where you may find other very similar options.

For shipping, ocean freight is probably best for the larger one.

If you'd rather a smaller one, which seems to be in stock currently:

https://www.solid.sale/Solid-Dish-Antenna/C-Band-Dish-Antenna/240cm-8ft-c-band-dish-antenna

In my understanding this should come in the box as shown, you could also try to check UPS/DHL/FedEx rates first for smallers ones, or national post (if it ships) might be cheaper.

Thanks

Here's the 2.4m dish I use for radio astronomy, I installed it at a low-RFI site. It's currently taken down and stored indoors after a storm, I'll reinstall it on my next visit. 

Just a note: these large dishes don't handle storms well, strong winds can rip the whole concrete base out of the ground and topple the dish. mine nearly went over, but I managed to save it.

[Marko Cebokli]

The dish/Yagi choice mostly depends on what is your working frequency. Pulsar's signal strength usually decreases with frequency, so 400MHz might be better than 1400Mhz. The problem with these lower frequencies is usually higher levels of man made interference.

A Yagi becomes a good choice, when the dish diameter would be smaller than about four to five wavelengths, or 20 dBi gain. In this case, you will get more gain with the same amount of metal in the form of a Yagi. The "discovery dish" is already below this limit at 1400MHz, a Yagi of the same weight would be better, but the advantage of the dish is, that you can easily change the working frequency, by changing the feed, making it a versatile antenna.

A minus of a Yagi is it's small bandwidth, usually about 5%, for a highly optimized one, and no way of changing its frequency, like with a dish feed. You get a bit more bandwidth with a cigar antenna (metal disks instead of sticks), but that one is significantly heavier, and has less gain than an optimized Yagi of the same length, not to mention weight. Not really practical for 400MHz.

Marko Cebokli

17.06.2026 02:54, je Ayushman Tripathi napisal

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[Robert Hamers]

Thanks… I hadn’t thought about (or have any experience with) these kinds of B2B sites.  I looked on Ali Express and there might be something there.  I am somewhat constrained by my backyard and my family’s wish to avoid having my backyard taken over by radio gear… So  6 feet / 2 meters is the biggest I can practically go.   I have to be able to move it (so a non-permanent installation) and ideally I’d like to be able to easily disassemble it and move it to a different location that I have access to.  So I’ve been looking primarily at mesh dish antennas, and especially ones with a petal structure that can be disassembled to fit in my car, and then reassembled.  

The B2B option seems like something I should look into more.  Also I’m perfectly happy to have something used and/or modify it myself  (e.g., my own feed, etc).

Thanks for your comments and suggestions!  If you come across something in the 1.5 - 2.0 meter range please let me know! 

Best wishes,

Bob

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From: sara...@googlegroups.com <sara...@googlegroups.com> on behalf of Ayushman Tripathi <ayushmantr...@gmail.com>
Date: Tuesday, June 16, 2026 at 7:54 PM
To: Society of Amateur Radio Astronomers <sara...@googlegroups.com>
Subject: [SARA] Re: Recommendations: Dish antenna or yagi for pulsar detection ?

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[Robert Hamers]

Hi-

Thanks very much for your comments!  They are very helpful.

I would adjust the working frequency as needed.  My home is in an urban location but I also have access to a rural location that I can drive to, as long as the antenna can fit inside my car for transportation.   That’s why I’ve been looking primarily at mesh dish antennas, and hopefully ones with a petal-like structure so that the dish can be disassembled into 3 or 4 sections.    But I’m limited to about 2 meters in size in my yard and due to family considerations.  With my horn antenna I’ve had very few problems with RFI in the 1420 MHz region despite being in a city, but the pulsar is also a much weaker signal.  But yes, I understand the tradeoffs in going to lower frequency having higher signal but also likely more noise.    I’m thinking of maybe giving it a try with my current 1m horn.  

Anyway, thanks again for your comments !  They definitely help me —

Bob

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From: sara...@googlegroups.com <sara...@googlegroups.com> on behalf of Marko Cebokli <s57...@hamradio.si>
Date: Tuesday, June 16, 2026 at 11:59 PM
To: sara...@googlegroups.com <sara...@googlegroups.com>
Subject: Re: [SARA] Re: Recommendations: Dish antenna or yagi for pulsar detection ?

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[andrew....@googlemail.com]

As I have discovered, the horn antenna is just a really good design for avoiding ground signals which explains at least partly your good H-Line results with your horn – pulsars generally involve moving to dishes which are more likely to pick up ground noise which might affect your pulsar observations – but best of luck and keep us all informed how you go!

Andy

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