Question for HAM radio operators

cland72

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Hey guys & gals,

I have a question about antenna gain. I plan on putting a vertical dual band (2m/70cm) antenna in my attic, and am looking at two models. I'll be driving this antenna with a Yaesu FT-7800R radio, pushing 50 watts max.

Diamond X200A Gain (dB): 6.0/8.0
Diamond X50A Gain (dB): 4.5/7.2

Here's the question: will I notice an obvious improvement in range by going with the X200A? If so, can someone comment on what sort of range/reception improvement I can expect?

I'm really leaning towards the X50A due to size and cost, but if the extra 1.5/0.8 dB of gain is going to be a night and day difference, I'm willing to pay more and deal with the extra length.

Thanks!
 

more_vampires

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I have a question about antenna gain. I plan on putting a vertical dual band (2m/70cm) antenna in my attic, and am looking at two models. I'll be driving this antenna with a Yaesu FT-7800R radio, pushing 50 watts max.

Diamond X200A Gain (dB): 6.0/8.0
Diamond X50A Gain (dB): 4.5/7.2

Here's the question: will I notice an obvious improvement in range by going with the X200A? If so, can someone comment on what sort of range/reception improvement I can expect?

http://www.antenna-theory.com/definitions/decibels.php
Skip the math, scroll down to the conversion table between dB and linear units.

If it were me building a shack, I'd always go with the bigger gain. I don't think it'll make all that much difference between the two, though.

My opinion. More gain = good, whether you can tell the difference or not. :)
 

cland72

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Thanks MV.

So based on that link, am I correct if I were to say that for dB 1-10, it is a 1:1 ratio of linear distance to dB increase? I.e., if I were to get 30 miles of linear range at 4.5 dB, I'd get 40 miles at 6 dB?
 

more_vampires

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For values approaching 1 dB, yeah. That crazy dB, you know, all non-linear and such.

There's so many variables, there's nothing else but to just try it and see how your DX/RX works out. HAM-types around here seem to care more about hitting the repeater north of here than their own personal antenna farms. I know a guy who hits it with a vehicle setup.
 

cland72

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Well, my primary need is to communicate simplex with friends that are 12 miles and 22 miles as the crow flies. Hitting repeaters around the area would be nice, and if I can accomplish my primary goal I should be able to accomplish my secondary goal (repeaters) with ease.

I think I'll stick with the X50A, since it will save me around $60 and, at this point, I'm just not convinced the X200A will do something for me that the X50A cannot do.

That being said, I'll wait a few days and see if anyone has any additional feedback.

Thanks MV!
 

more_vampires

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Anytime, friend. With luck, someone will chime in with something really cool.
 

Str8stroke

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I run the X300, I had the X200 but sold it to a new ham. My X300 sits only 12 feet off the ground! I run LMR400 all connected to a 7800. I can easily do 10 plus miles simplex with about 20 watts on 2 meters. So a X50 sitting higher running 50 watts should work fine. Of course topography and conditions can affect that. I strongly suggest LMR400 and Amphonol connectors.

FYI, when 2 meters opens up (rare event) I have had several QSO's over 100 miles simplex! Crazy I know.

Keep in mind, the antenna set up is the most important part of your station. SO invest wisely.
 

MrMom

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An antenna does not make gain, it subtracts signal from one direction and adds it to another direction. To have 2dB gain in one direction, there must be a 2 dB reduction in another direction.

I have or have used all the antennas mentioned in this thread. Your best performance increase will be to get the antenna outside. Elevation is king with VHF and UHF. It boils down to line of sight plus 20% or so. There are many web based line of sight calculators.

The X50 can be spray painted flat black to have a low visual impact. I use the X50's on both of my repeaters and X500's at home.

Use high quality LMR400 type coax. DX Engineering 400 flex is great stuff for a buck a foot.

73

K2LED
 
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Str8stroke

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I forgot to mention what K2LED said. I too painted mine. I used the Camo paints from Home Depot. Olive drab and brown blend in nicely if you have trees or a dark roof like mine. I also painted my 10 Meter vertical Gainmaster. I love this antenna. It is on a 40 Foot Pushup pole. I only keep it around 30 feet. The tip just barely clears my house. It too has LMR400. Confirmed QRP (5 watts) QSO's on 10 meters from Louisiana to Japan when 10 is open. If you are trying QRP I find that the less loss is super important!!

I had the super flex on my 8 Band Buckmaster OCF. That is some super nice stuff. This was until my German Shepard found it about a inch deep in the grass. She chewed it up badly. I replaced it with regular LMR400 and ran it through the air! I also forgot to mention the other gear I am running. Alpha Delta 4B switch and a Flex 3000 SDR.
 

cland72

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An antenna does not make gain, it subtracts signal from one direction and adds it to another direction. To have 2dB gain in one direction, there must be a 2 dB reduction in another direction.

I have or have used all the antennas mentioned in this thread. Your best performance increase will be to get the antenna outside. Elevation is king with VHF and UHF. It boils down to line of sight plus 20% or so. There are many web based line of sight calculators.

The X50 can be spray painted flat black to have a low visual impact. I use the X50's on both of my repeaters and X500's at home.

Use high quality LMR400 type coax. DX Engineering 400 flex is great stuff for a buck a foot.

73

K2LED

Unfortunately this isn't an option. HOA board is a bunch of sticklers. Thank you for the feedback.

I went with the X50A and installed it today. So far, so good.


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Spork

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Wouldn't a yagi be about the best option for long distance? Should be small and easy to move for aiming on vhf or uhf. Then if everyone had ssb radio's I bet you could go some ridiculously good distances on vhf.
 

cland72

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Yes, if I were only communicating with one person. Unfortunately my friends are spread out all over. Thanks for the suggestion though!
 

PhotoJim

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I'd go with the highest gain omnidirectional antenna I could, if you want to be able to talk to people in all directions. I'd also recommend you get the antenna outside, if you can, and as high as is reasonably practical. That will give you the best range.

It's surprising how well you can do on 2m/70cm simplex, though. Even at quite low power you might be surprised at how well you can do once you get an antenna at a decent height or outside (or both).

I run an IRLP node at my home and for now, I have a 1/4-wave antenna in my shack at 10 watts. The range is at least 5 km. It will be a lot better once I get the antenna outside.
 

cland72

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I'd go with the highest gain omnidirectional antenna I could, if you want to be able to talk to people in all directions. I'd also recommend you get the antenna outside, if you can, and as high as is reasonably practical. That will give you the best range.

It's surprising how well you can do on 2m/70cm simplex, though. Even at quite low power you might be surprised at how well you can do once you get an antenna at a decent height or outside (or both).

I run an IRLP node at my home and for now, I have a 1/4-wave antenna in my shack at 10 watts. The range is at least 5 km. It will be a lot better once I get the antenna outside.

Unfortunately, because I live in a neighborhood with an HOA I opted to keep the antenna inside the attic and avoid potential complaints, not to mention OPSEC (I like to maintain a very low profile). I did end up going with the X50A because I didn't really have room for the X200A (plus it provided marginal gain improvement). I am happy to report that it works very well, and I'm able to make simplex contact with a friend approx 20 miles away with a signal strength of S5 and almost no background noise. Mission accomplished!

Thanks to everyone who contributed to this thread.
 
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Str8stroke

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For my base rig, I run a Yaesu FT-7900R and the X300A. I had the 200 before, but a new ham begged me for it and I sold it. After upgrading, I barely noticed any improvement. What gave me the most improvement was changing out the RG58 (think it was old Browning) coax to LMR400. It was a noticeable improvement. I have a HOA too, I painted mine olive drab and have it in a umbrella stand 11 feet off the ground in my back yard. When the band opens up it is a blast. I have several QSO's over 100 miles simplex. Talk about fun!

I just upgraded my handy talk to the Yaesu FT1D. Neat radio. I am still learning it. Our club just upgraded to the Yaesu Fusion repeater. So I can't wait to play.
 

cland72

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I ended up buying 25 feet of RG-213U and going with that. Based on the short length of my run, I decided I wouldn't see a vast difference in performance between that and LMR400.

I'm sure you'll like your new Yaesus. I have owned a few different brands (Icom, Yaesu, Puxing) and Yaesu has always been my favorite. The menus seem pretty straight forward, and they seem pretty reliable. Currently the X50A is being driven by a Yaesu FT-7800 and is working great.
 

Str8stroke

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That is a solid set up cland72. The menu on the FT1D isn't very straight forward. lol It is kinda tricky to learn. But so far, I love the radio! I have only had it about a week now. But it is tricky compared to my FT-60. I may sell my trusty FT-60. Not sure yet, cause it does make a great back up rig.
My HF rig is a Flex 3K running it through a Buckmaster 7 band inverted V. All hidden in the back yard.
 

Jumpmaster

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RF gain, power, etc. all follow the inverse square law...

Gain is just one part of the equation...there's also feed line loss, antenna height, frequency, time of day, etc...there are many, many, many variables that go into successful DX.

I have an ATAS 120 on my truck and use it with an FT-857...generally, if I can hear them, I can work them with only 100w or less. I've talked as far away as the Ukraine while mobile and during the day...I think it was 20m.

Anyway, I'm looking for a new home right now and will only consider places with no HOA and no deed restrictions. :) If you are in an area where you cannot put up an outside antenna, you might want to look into PSK31. I have a diplole under the eave of my house and it works great...no one can see it from the street and you don't have to use much power for PSK31. I use an Elecraft KX3 for PSK31 and also have an FT-897 that I can use for digital, but mostly voice. The antenna in my yard is an R5 vertical. It works ok, but it would be nice to have a Yagi at some point.

Just a few ideas I thought I'd throw out there...most of my radios are Yaesu because one you get used to their menus, they are pretty similar throughout their various models...
 

cland72

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SS, sorry to hear the menu isn't as clear on the FT1D. I have a FT270R and VX7 and personally love the menus. Weird that Yaesu would deviate from what I think works very well.
JM, thanks for the head's up. I've been a tech since 2010 and haven't gotten around to studying for my general, but am looking forward to working on HF one day.
 

BarryH

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Another stealthy (and portable) option is a wire J-pole. I've had good luck with these deployed in an attic for friends (and some younger hams) with similar limitations, and deployed from a tree branch or other support when traveling or camping.

You can build them fairly easily or find pre-assemble versions without too much cost.

Here is a link an old QST article with plans and info:
http://www.tgc-ares.org/DBJ-2 Roll up.pdf

73 de K4WX
 
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