Is a Yagi what I need?

[KC4KLM]

I searched before posting and didn't find a answer specific to my question.

I have tried a Diamond X50a and Comet CX-333 at 30 ft. AGL, and both work great for every repeater I need to hit as far as 40 miles with great Rx and Tx strength, except for one. The one 2 meter repeater I can't get good Rx on very well is 31 miles away. They can hear me a little better than I can hear them. I don't know what the obstruction might be... terrain or a building or something else. However, I was thinking of adding a 2M Yagi antenna to improve my directional signal for when I need to get into this specific repeater. I am using a mobile 50w radio.

Is a 2 meter Yagi the best approach to improve my signal to this one repeater, or would some other antenna configuration work better for this application?
Thanks for your time.

 

[mmckenna]

A Yagi would focus your energy towards the repeater, and improve reception.

Without knowing all the details, locations, topography, buildings, and all the hundreds of other variables, no one would be able to tell you if it's going to 100% fix the issue or not. You might want to try building a Yagi antenna, they are not hard. Give it a try and see if it helps.

 

[KC4KLM]

Thanks for the reply. I am not looking for anyone to confirm that it will work, but rather, confirm that a Yagi is the best choice for what I am trying to achieve. I am going to build one if most of the responses agree with that.
Have a great day

 

[alcahuete]

Yagi is the answer to everything, be it HF, VHF, or UHF. Well...that's my opinion anyway. I don't waste time with anything else these days unless it's on a vehicle or repeater.

Will it fix your issue? Maybe, maybe not. If you're blasting your RF straight into the side of a building, not going to matter much if you have an omni or yagi. Same on the receive side. But generally speaking, yes, it should help.

 

[KC4KLM]

Yagi is the answer to everything, be it HF, VHF, or UHF. Well...that's my opinion anyway. I don't waste time with anything else these days unless it's on a vehicle or repeater.

Will it fix your issue? Maybe, maybe not. If you're blasting your RF straight into the side of a building, not going to matter much if you have an omni or yagi. Same on the receive side. But generally speaking, yes, it should help.

Excellent. I appreciate your input. I guess it won't cost too much to try it out and see what happens.

 

[kh2]

I was having similar issues as the OP and headed to the Yagi. I live in a bowl with monster trees., doing a bit more research I landed on the Log Periodic specifically the Elk Antenna 2M/70CM. In my situation I am very pleased with the reach and the bandwidth. I even have a couple repeaters I could never touch and didn't expect to in the opposite direction IE rear without rotating the antenna and i hit them fine as well. - I am running 10W on a Icom 705.

My 2 cents your mileage may vary but it worked in my situation.

 

[mmckenna]

My 2 cents your mileage may vary but it worked in my situation.

Log periodics are great if you need the bandwidth. A bit less gain than a similar size Yagi.

They do make dual band Yagi's that would also be a good fit if dual band was needed in a limited space.

A lot of fun antennas to play with, part of what makes amateur radio a fun hobby.

 

[AK9R]

They do make dual band Yagi's that would also be a good fit if dual band was needed in a limited space.

DX Engineering still lists the Cushcraft A2706S and A2710S which are dual-band 2m/70cm Yagi antennas. The A2706S has three elements on each band and the A2710S has 5 elements on each band. Cushcraft was part of MFJ which has stopped production, so supplies of these antennas at DX Engineering and other dealers may be limited.

 

[G7RUX]

I searched before posting and didn't find a answer specific to my question.

I have tried a Diamond X50a and Comet CX-333 at 30 ft. AGL, and both work great for every repeater I need to hit as far as 40 miles with great Rx and Tx strength, except for one. The one 2 meter repeater I can't get good Rx on very well is 31 miles away. They can hear me a little better than I can hear them. I don't know what the obstruction might be... terrain or a building or something else. However, I was thinking of adding a 2M Yagi antenna to improve my directional signal for when I need to get into this specific repeater. I am using a mobile 50w radio.

Is a 2 meter Yagi the best approach to improve my signal to this one repeater, or would some other antenna configuration work better for this application?
Thanks for your time.

Antenna gain should help, although if it is an obstruction causing the issue then it might not help as much as one would hope. It is worthwhile using one of the online path analysers to see if you can get some insight as to what the path profile is like.

If the path is reasonably clear then the issue might be one of interference, so an antenna with some gain may well help quite a bit, provided the interferer isn't in the direction you're interested it!

 

[ecps92]

Thanks for the reply. I am not looking for anyone to confirm that it will work, but rather, confirm that a Yagi is the best choice for what I am trying to achieve. I am going to build one if most of the responses agree with that.
Have a great day

Amateur Radio is about, many times, Experimentation.

What works for me, may/maynot work for you.

 

[k6cpo]

It's all about location, location, location. The antennas you have are perfectly capable of hitting that repeater, IF there aren't any obstructions between you and the repeater. If there's a substantial hill, mountain, or buildings in the way, then a Yagi isn't going to help much either.

I live in a part of San Diego that is up on a plateau with unobstructed views in all directions. For years I used a Comet GP-1 antenna and could consistently hit Mount Laguna at 47 miles, Mount Palomar at 41 miles , Catalina Island at 88 miles and Signal Hill (Long Beach) at 95 miles. Granted, Catalina and Signal Hill are mostly over water, but I have coverage for a lot of other repeaters in the area.

 

[KC4KLM]

Thank you all for your replies, opinions, and good info. I now will go through some trial and error and see what solution works best.

 

[G7RUX]

One of the interesting consequences of using an antenna with some decent directionality is that you should find an improvement in the received noise level. A permanent yagi pointing at a specific repeater might seem like a step too far but it can most definitely be worthwhile if you use that repeater a fair bit.

I have had an antenna system using three 5-ele 2m Yagi antennas, mounted at 120 degree spacing and a coax switch to select between them...the antenna patterns are wide enough that you get decent 360 degree coverage with some moderate gain everywhere and it avoids the need for a rotator.

 

[KC4KLM]

One of the interesting consequences of using an antenna with some decent directionality is that you should find an improvement in the received noise level. A permanent yagi pointing at a specific repeater might seem like a step too far but it can most definitely be worthwhile if you use that repeater a fair bit.

I have had an antenna system using three 5-ele 2m Yagi antennas, mounted at 120 degree spacing and a coax switch to select between them...the antenna patterns are wide enough that you get decent 360 degree coverage with some moderate gain everywhere and it avoids the need for a rotator.

Great info, thank you. That is an interesting setup with the three Yagis.

 

[G7RUX]

You can also, if you feel so inclined, use all three and combine them with specific phases to steer the beam...messy but works surprisingly well.

 

[KC4KLM]

Thanks all. I borrowed a 2m Diamond yagi and can pull in the weak station I need to reach very well now. S9 receive and much less noise with good Tx signal reports. So that is the antenna format I will go with, and eventually put it on a cheap rotator. The surprise was how well I can still reach other stations that are not directly in the main beam width.
Thanks again

 

[G7RUX]

Thanks all. I borrowed a 2m Diamond yagi and can pull in the weak station I need to reach very well now. S9 receive and much less noise with good Tx signal reports. So that is the antenna format I will go with, and eventually put it on a cheap rotator. The surprise was how well I can still reach other stations that are not directly in the main beam width.
Thanks again

I suspect that you’ll find you have a local-ish source of noise from sort of behind the direction you’re wanting that affects the receiver with an omni antenna; the directivity of the yagi helps reduce that, reducing the SNR of the receive system.

Since the e-plane radiation pattern of a 3 or 5 element yagi is pretty wide on the main lobe you will see less directivity than you might have expected, with a typical 5-element giving a -3 dB beam width of perhaps 60 degrees and a -20 dB beam width of around 120 degrees. The back-to-front ratio would probably be something like 16-20 dB which is where the big benefit of a modest yagi comes from; rejecting that interference from behind.

I’m assuming you’ve mounted the yagi vertically, in which case the front-to-back ratio is rather better and the front lobe can be wider.

 

[KC4KLM]

I suspect that you’ll find you have a local-ish source of noise from sort of behind the direction you’re wanting that affects the receiver with an omni antenna; the directivity of the yagi helps reduce that, reducing the SNR of the receive system
.....

This is helpful information; I appreciate your time. Yes I have it mounted vertically, and I think you are right about the more local source of noise. I am really enjoying the performance of this fairly basic yagi and am already wondering, "what if I went with a 10-element beam instead of 5?" Ha! Thanks again.

 

[alcahuete]

This is helpful information; I appreciate your time. Yes I have it mounted vertically, and I think you are right about the more local source of noise. I am really enjoying the performance of this fairly basic yagi and am already wondering, "what if I went with a 10-element beam instead of 5?" Ha! Thanks again.

As I said up above, yagi is the answer to everything. To expound on that, more elements is the answer to yagi.

 

[KC4KLM]

As I said up above, yagi is the answer to everything. To expound on that, more elements is the answer to yagi.

I just had a clear QSO on a repeater 101 miles away, from the yagi in my attic. I am sold!