Antenna for FT-991a

nick59349

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Hello, I’m building a home base system using an FT-991a and need some advise on which antenna to buy? I’m a newbie.
Thanks.

Nick
 

KB4MSZ

Billy
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Oh boy. Quite a question for a Shack-In-A-Box radio. There are a lot of questions that need to be addressed for this type of rig. Are you aiming at primarily HF operation? Plan to also operate VHF/UHF repeaters? Possibly VHF/UHF weak signal SSB?

The rig has two antenna ports, one for HF and 50 MHz, and the other for VHF/UHF. If simultaneous operation is desired then multiband antennas for each of these ports will be needed, or possibly diplexers/triplexers to use higher gain monoband antennas. It all depends on what your target is. This type of rig has very diverse capabilities.
 

nick59349

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Thanks for responding. I’ll probably want simultaneous use so dual antennas would probably be best unless the make a single one that does all function that I could diplex in?
 

KB4MSZ

Billy
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A single one to do the job? Not with that radio. This radio isn't like a police scanner that you can connect to a discone antenna and be done with it.

With just the HF portion alone (3 to 30 MHz), there are 9 bands of frequencies involved. A simple half wave at 28 MHz (10 meters) can be as short as 16', at 3.75 MHz (80 meters) it would be 120' long. Your radio also includes 160 meters, and yes, it is double the length of 80 meters.

There are ways to accomplish what you want. Can I assume that since this is a transceiver your intention is to be "on the air" as a licensed Ham operator? If so, then the setup of the antennas is more critical than just using the radio to listen with. Proper equipment will be needed such as a SWR (Standing Wave Ratio) meter, feed point assembly parts, coaxial cable assemblies, etc.

In the HF spectrum, several monoband antennas can be installed for the bands of your choosing and each can be supplied with a feed cable which returns to a switch in your shack. There are also multiband HF antennas (verticals, wire) which provide a wide coverage but may or may not be a compromise depending on the type of communication you are after. On the higher portions of HF (say 20 meters and up) beam type antennas can provide outstanding performance, but of course require a mounting structure such as a tower and a means of rotating them. The antennas are mostly limited by the available real estate you have to work with.

In the VHF/UHF spectrum, there are repeaters, both FM analog and digital, and these are usually vertically polarized stations. If you wish to try your hand at VHF/UHF SSB operation then a horizontally polarized beam would best suite the need. In the VHF/UHF world, HEIGHT IS EVERYTHING.

Maybe some others with a better knowledge of past posts can direct you to information already prepared which would be more complete (and better compiled) than I have done here.
 

nick59349

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I figured it would a little more complex than I was expecting. I guess I should back up a bit. I’m working on getting my technician then general at some point. Both licenses would be helpful for my job. I’m looking at an all band radio that I learn on. I guess I should have asked advise on that first. The icom ic 705 would probably good too? I was looking at the 991 because it was priced good and had everything. I live on the top of a hill with pretty good reception I think.
 

KB4MSZ

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The Icom 705 is a "QRP" radio, this meaning low power (maximum of 10 watts). It is meant for portable use, such as a field day event. It's lower power requirements would be more suitable for battery or solar operation. The Yaesu 991a is a "full power" rig, meaning it outputs 100 watts up to 50 MHz (6 meters) and 50 watts on 144 MHz (VHF, 2 meters) and 420 MHz (UHF, 70 cm) bands.
 

popnokick

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The FT-991A will serve you well in your amateur radio pursuit. Examples of multi-band antennas that I use with a similar radio (Icom 7100) are 1) a 160-6 Meter Off-Center Fed Dipole with a tuner that gets me on all the ham bands in that range with a tuner. It is more than 280 feet of wire with 50 feet of coax feed line. It is of course horizontally polarized. 2) On the other antenna connector on the radio, I have a Diamond V2000 which is a multi-band vertical antenna covering 6M, 2M, and 70cm. To take full advantage of your 991A these are the types of multi-band, lower cost antennas you'll need to evaluate. And you can spend much more and use more real estate. Going the other way (less cost, less real estate) is when compromises will start to kick in, and you'll need to decide what you want to give up in bands and performance.
 

wcsd45

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Wow. Good, huge and right question. There are countless options. One of the big considerations is whether you have HOA or covenant restrictions, and this was my situation imposing significant option boundaries.

My first thought is that antenna selection should be a thoughtful process with a plan. A plan will serve you well. As you grow into the hobby, you should expect that the plan will change with as you earn experience and want to try new antennas.

Second thought is to think about lightning protection and grounding. ARRL book: Grounding and Bonding for Radio Amateur (Amazon) is an essential read, and it will help develop both antenna and station building plans. It's safety stuff here. Just do it. I preferred the paperback version. Better for pictures and diagrams.

This is one of my favorite grounding write-ups:

Third thought is take a look around your QTH. Can you do a tower or mast? Lotsa room in backyard? Roof mount? Where will you set-up your radio and what will it take to get your feedlines to the antenna. What can you do about antenna maintenance and will you be able to get at them seasonally (tough winters here).

Fourth thought is budget. Yep, there are costs to do antenna systems well, and it is not a bad thing to spend proportionally more on antenna systems. You can do them crazy complex or simple straight forward.

Fifth thought is join local amateur radio club and ask those with experience (elmers) a good approach having worked through the above.

Sixth thought is, fear not the antenna forums here, but also at eham.net and qrz.com. They are daily reads for me.

For starters, think a multiband (2M/70cm) for V/UHF. For HF, I was thinking fan dipole, but many options are out there and what antenna type is better (no such thing as best) will be subject of many and passionate opinions. One of my elmer's sage advice was that you could as same question to 20 guys and get 20 different answers.

Good Luck, Questions welcome. Email at qrz.com is good.

Chuck KC9QBY
 

nick59349

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Thanks much for all the information. I have a large front yard but it’s full of giant fur trees. The big issue is my wife’s restrictions of them not being seen. From what I’ve seen the VHF/uhf antennas are a single pole. I might be able to run in up through one of my bushy trees and it will be hidden at least in the summer. As for the Hf antenna not sure how I’m going to do that one. My radio will be in the basement so running the coax out will be a piece of cake.
 

K9DWB

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Good comments given already. I guess one of the big things to consider is how much room outside to place antennas will be available. Yes, some can be up in the trees literally. We already have noted down the restriction your wife can't see them. Is not letting her out of the house something you can get away with?

OK seriously, there's several options and directions to go for antennas to cover HF and VHF/UHF. I think the last 2, VHF and UHF may be easier as these might be smaller. One choice is something like what I run as an external dual band for my HT, the only radio in my shack right now, unless you want to swap. I have a dual band Tram 1480 that covers 2M and 70cm/440. Alone it is 8' tall vertical and omnidirectional. If I were you though, get a better branded similar in spec, like a Diamond X200 or better. This Tram is an OK starter for me and how I'm using it, but it also is in my plans to replace it if anything happens to this one. I felt the need to get on the air reasonably quick and didn't have the finances to tie up in an antenna at about twice the cost of this one.

On HF there's options, some choices than others. If you have the space, an EFHW/end fed half wave such as what MyAntenna offers may catch your eye for one direction/choice. There's lots of others, but decide what you really need/want to accomplish and if there's bands you aren't interested in, why get antennas to cover that band.

Consider things like power, ground, etc. for the radio as well, and where exactly it will be setup.

Lots of things to consider to keep you busy for a while. Best wishes for your success, and keep asking the questions. Post images when you get some progress in the setup.
 

alcahuete

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Fantastic discussion, gents!

A crapload of wires up in the trees is probably your best bet. You could run a HF vertical up into the trees as well (like you would the VHF/UHF), but the wire will probably work better.

One thing you can also use is a flagpole antenna. It's a compromise antenna that is often used in HOAs, but they also look good, and would hopefully keep the wife happy.
 

djeplett

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I have an FT991A and before that a Kenwood TS590S, both with internal antenna tuners. I put up an 80M inverted vee and have been able to use it on 80, 17, 15 and 10M with just the internal tuners. Obviously, 80 would be the only band not compromised with terrible radiation patterns, but I have worked 13 different countries and 4 continents with this extremely modest setup. I also run a Comet GP15 for 6M, 2M and 70cm. With the FT991A you have to use a couple coax switches with this because the one antenna port is for HF and 6M and the other is 2M/70cm but that's inexpensive also.

If you were to put up a fan dipole you could increase the number of bands you could tune up, also.
 

nick59349

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After a bit of research I came up with a couple options that might work but would like some input. I'm thinking th Hustler 5BTV 5 band for the HF bands I want and the Comet GP-15 for the VHF/UHF bands. I think I can hide them both well enough. What do you guys think?
 

popnokick

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The Hustler 5BTV is 25 feet tall. All verticals need a field of buried ground wires or mat of chicken wire buried (or laying on) the ground for the antenna to perform well. It should also be mounted away from other structures such as houses, buildings, and trees and "in the clear" of obstructions (which makes it hard to hide). How many feet away from those obstacles will it be when it is installed? It is possible to roof mount it, but then you'll also need a lot of ground radial wires, since roof mounting without radials produces very compromised performance.
 

tweiss3

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The hustler isn't a bad, but if you read G0KYA's book on Antennas for Small or even no Gardens, you need a minimum of 32 ground radials, and they should be at least as long as the antenna is tall. Also, you won't get high angle takeoff on 40/80 and won't get local near vertical.
 

nick59349

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I guess I missed that part. Would the EFHW-4010 from myantennas be a better choice?
 
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