1 ant. to 3-4 or more revevers/transcevers how to?

[brandonoh777]

I am getting more and more into all this...started with a rtl SDR dongel..then 2-3 of them (the 're soo cheep) already had an icom a6 handheld for my pilot bag. now I have built my 1st VHF air band tuned antenna!!! so far so good everything works great and the new antenna on about a 35 foot mast off my 2nd floor apt balcony is picking up signal I NEVER was and at much greater strengths!!!... So I was happy for a day or two... now I am thinking how can I connect this new VHF band tuned antenna up to several receivers and the one transceiver with as little as possible signal loss, and not take out a mortgage to do it

The end goal here would to be maybe have one antenna for each major band UHF,VHF and eventually HF and maybe lower as I am dealing with a balcony that's about 10 foot by 5 foot so not so much room for many antennas I have 4 "other desktop computers running in my home network so theoretically I could maybe do 4 rtl sdr's one on each computer maybe 5 if you include my main desktop and I have the A6 transceiver (which I may occasional want to transmit on) which raises another question.. can I do that well in a split antenna setup? or would I need a dedicated antenna for the transceiver and then one for all of the receivers?

The 4 "other: computers" with sdr's will prob be used to feed audio to stream on the net.. likely liveatc.com as there IND feed seems to have gone down over the last 8 months or so and I am 4 miles from the airport.!! and as a pilot I am mostly into the air band.

Lastly I built a 1090 mhz tuned collinear/coaxial antenna to be used with ADS-B exclusively and that one will be used with likely just one computer.

From some research online I hear just by the physics of it.. you lose about 3db when a signal is split but beyond that ill need the more expert advise from you all. Does that mean a 4 way splitter loses 3db for each one or 6? is it the same as 2, 2 way splitters? and can some of this signal loss be minimized by a pre amp between the antenna and the splitters?

any recommended product links would be greatly appreciated

PS I am usually flying all over the Midwest below 10,000 in the middle of the night or early mornings (just the freight and me) so I welcome anyone that can transmits/receive in the VHF air band on one of the common air to air freqs or air to ground as a chat buddy one some of these long boring middle of the night trips so if your in IN,IL,OH,MI,KY,WI and occasionally MN,IA,MO,TN.WV,PA let me know!!

Brandon

 

[mmckenna]

so far so good everything works great and the new antenna on about a 35 foot mast off my 2nd floor apt balcony is picking up signal I NEVER was and at much greater strengths!!!

A good external antenna will make a huge difference. Getting it up high and in the clear will do more to improve your reception than anything else. Glad it worked out for you.

The end goal here would to be maybe have one antenna for each major band UHF,VHF and eventually HF and maybe lower as I am dealing with a balcony that's about 10 foot by 5 foot so not so much room for many antennas I have 4 "other desktop computers running in my home network so theoretically I could maybe do 4 rtl sdr's one on each computer maybe 5 if you include my main desktop and I have the A6 transceiver (which I may occasional want to transmit on) which raises another question.. can I do that well in a split antenna setup? or would I need a dedicated antenna for the transceiver and then one for all of the receivers?

There are ways to transmit and receive on the same antenna, but it isn't cheap and requires the transmit and receive frequencies to be in specific windows to work. Not what you really want to do. Keep your transceiver on a separate antenna with as much spacing between the scanner antenna and the transmit antenna as you can get.

From some research online I hear just by the physics of it.. you lose about 3db when a signal is split but beyond that ill need the more expert advise from you all. Does that mean a 4 way splitter loses 3db for each one or 6? is it the same as 2, 2 way splitters? and can some of this signal loss be minimized by a pre amp between the antenna and the splitters?

Right, every time you split the signal, you are going to loose at least half of it. This can be overcome by using a preamplifier on your feed line before it gets to the splitter. Preamplifiers will boost everything in their range, and while this is good, keep in mind that it will also amplify the things you don't want. Since it sounds like air band is you interest, you need to be careful that any nearby FM broadcast transmitters don't wind up wiping out what you want to listen to. Might be a good idea to consider a "trap" to block out the FM broadcast band.

any recommended product links would be greatly appreciated

I don't have any recommendations. All the receive multi-couplers I have at work are band specific and expensive. There has been a lot of talk about these on the site, so doing a search would probably turn up a lot of information.

PS I am usually flying all over the Midwest below 10,000 in the middle of the night or early mornings (just the freight and me) so I welcome anyone that can transmits/receive in the VHF air band on one of the common air to air freqs or air to ground as a chat buddy one some of these long boring middle of the night trips so if your in IN,IL,OH,MI,KY,WI and occasionally MN,IA,MO,TN.WV,PA let me know!!

I'm west coast, but sounds interesting.

 

[brandonoh777]

a coasty huh? that's cool so your day job involves RF as well? mine does just in the air band. I mean I knew the radio basics as every pilot who does it for a job does but I am getting soo much deeper into it now. its kinda addictive!!! ya I have the 1/4 wave grand plane antenna (sized for apx 124 mhz...about the middle of the air band) that was my 1st build up on about 30 feet of mast (and then my 2nd floor balcony is already about 10-12 feed off the ground so I got about 40 or so feet above ground level and is does real good!!!!! I just cant put up a bunch of masts and about the farthest I could ever get one ant from the other is about 10-12 feet laterally..... so I am going to need another 1-2 masts...that sucks ill need one just for the transmitter...unless I just use a switch..to isolate that ant to the transceiver only as my need to transmit is fairly rare at this point.... could I put the 1090 ADS-B antenna on the same mast as the VHF air band one...maybe a lil lower down as its just a piece of PVC pipe on the outside and nice and straight..might be able to mount it on the same mast as the VHF...or not a good idea?

Also ive heard and seen much on you tube about antenna turners...but they run a lot of $$$ for only limited use. will I really get that much better reception/transmission fine tuning it with an antenna analyzer? all I did was measure as princely as I could went I cut the radials and the center element.. seems to work pretty good

 

[mmckenna]

Was a coasty, now a civilian. My "day job" is a telecommunications engineer, so I do get to play with radio and big phone systems full time.

Yeah, it can get addictive and expensive. Not a poor mans hobby, that's for sure. The real trick to it is figuring out a way to get the job to pay for part of it. You have your VHF air band radios with a 10,000 foot high antenna, I've got a room full of toys, I mean, tools….

Getting a mast on either side of your balcony would be the way to go. Put your transmit antenna on one and your scanner antennas on the other. As for the ADS-B antenna, you can put in on the same mast as the transmit antenna, just lower down. Vertical separation works best for vertical antennas.

Antenna tuners don't do much for receiving. Basically they'll hide issues when transmitting, they don't actually fix the issue. If your receive antennas are designed right, they'll be broad banded enough to work just fine. I wouldn't spend money on an antenna tuner unless you were transmitting on the HF bands. Instead, put your money into quality coaxial cabe, it'll make the most difference based on your mast limitations.

 

[brandonoh777]

i ran RG-6 (sat TV) coex form the ant to my hand held...or SDR as of right now...also have some RG-59 i can use. will the same ground plane type antenna i made work for transmitting as well? If so ill just make another one of those as my transmit antenna heres a pic of it https://www.dropbox.com/s/dp1uq8w4a9ofifw/20150101_213705.jpg?dl=0

 

[brandonoh777]

I don't have a HAM licence as of yet..but im kicking around the thought of getting it.i will eventually want to at last listen in the HF and maybe lower bands so therefore ill need to figure out some type of antenna for the say 2-30 mhz band I would like to start out seeing if I can pick up some of the Trans Atlantic HF ATC (dono if I can get that all the way over in Indiana or not?.. im assuming my right to transmit on the VHF air ban as a pilot apply's to me on the ground at home as well...as long as im not causing any disruption etc.

 

[brandonoh777]

You have your VHF air band radios with a 10,000 foot high antenna, .

Ya I did some listening on a few of the ACARS freqs from altitude and man its consent...alot more transmissions than I was getting from the ground.... I am going to try one of the android acars decoders and plug my phone mic into the audio out on comm #2 and tune it to an acars freq in flight and see how many hits I get on a few hour flight covering several Hundreds miles from 6,000-10,000 feet high... should be impressive!!! U ever play around with the rtl SDR's? I just got 2 of them amazing lil cheep things!!!

 

[brandonoh777]

ALSO....sorry keep thinking of things..... I ordered one of the HAM IT UP up convertors to be able to listen to the lower HF bands with the rtl SDR... know anything about it or have any experience with it or heard good/bad things?

 

[kruser]

im assuming my right to transmit on the VHF air ban as a pilot apply's to me on the ground at home as well...as long as im not causing any disruption etc.

Better look into the rules. They are strict and carry large fines.

I know companies can contact their aircraft in the air in the upper part of the air band but I don't think general chit chat is allowed from ground to air.

 

[brandonoh777]

Better look into the rules. They are strict and carry large fines.

I know companies can contact their aircraft in the air in the upper part of the air band but I don't think general chit chat is allowed from ground to air.

we do it air to air all the time there are several "chat freqs" not official biz necessarily sometimes an informal pirep or 2 but 75% just chit chat

 

[majoco]

Pilots, engineers, ground crew, dispatchers etc have to have some formal education in the use of their radios on VHF Airband - all pilots and quite a few ex flight engineers have an FRTO licence built in to their qualifications. The pilot-to-pilot chat frequencies are strictly unofficial (123.45 etc) and if you missed a call because you were not on the correct frequency you could be in deep doo-doo. An unauthorised user of an airband frequency would be in it even deeper and could lead to massive fines and confiscation of ALL your gear. The FAA and the FCC take a dim view of "interfering with the operations of an aircraft in flight" even if you are a pilot. You will still be an unlicensed person operating an unauthorised unlicensed ground station.

 

[Wally46]

I'm in the easternmost part of Iowa and have heard a couple pilots chit chat before. Maybe it was you lol

 

[mmckenna]

i ran RG-6 (sat TV) coex form the ant to my hand held...or SDR as of right now...also have some RG-59 i can use. will the same ground plane type antenna i made work for transmitting as well? If so ill just make another one of those as my transmit antenna heres a pic of it https://www.dropbox.com/s/dp1uq8w4a9ofifw/20150101_213705.jpg?dl=0

RG-6 is usually good for most stuff. If it's working, then leave it be. If your runs are really long, you might want something better.

That antenna looks good. 1/4 wave ground plane, lots of bandwidth. It would likely work just fine for transmitting, depending on where it's resonate. I'm going to guess you made it for VHF air band, so it should work fine there, and -might- work just fine on the 144-148 amateur radio band. Would work just fine for receiving elsewhere in the VHF band.

I just installed a 1/4 wave antenna on my dad's new truck. I have a analyzer at work that lets me look at the antenna performance. A simple 1/4 wave antenna has really good bandwidth. Setting his for the 2 meter amateur band showed low SWR well up into the 160 range and down near 120MHz. If you need a good overall VHF antenna, the 1/4 wave like the one you built is hard to beat.

 

[mmckenna]

I don't have a HAM licence as of yet..but im kicking around the thought of getting it.i will eventually want to at last listen in the HF and maybe lower bands so therefore ill need to figure out some type of antenna for the say 2-30 mhz band I would like to start out seeing if I can pick up some of the Trans Atlantic HF ATC (dono if I can get that all the way over in Indiana or not?.. im assuming my right to transmit on the VHF air ban as a pilot apply's to me on the ground at home as well...as long as im not causing any disruption etc.

The technician license test is fairly easy. If you are already building antennas and putting coax in, it sounds like you are well ahead of many.
For the HF band, you'll need a dedicated antenna to transmit. Not sure what would work best for you location with limited space, but there is a lot of stuff out there. Some simple wire antennas might work well, and you might be able to rig something up using your existing poles.

Not sure exactly what the rules are about transmitting on Air VHF, you'd likely want to look up the specific rules to be sure.

Personally, I think you'd have a lot of fun with a basic amateur hand held radio up in the air. Not sure how well it would work in a cockpit, or even if your company would allow it, but being up 10,000 feet should result in some amazing coverage.

 

[mmckenna]

Ya I did some listening on a few of the ACARS freqs from altitude and man its consent...alot more transmissions than I was getting from the ground.... I am going to try one of the android acars decoders and plug my phone mic into the audio out on comm #2 and tune it to an acars freq in flight and see how many hits I get on a few hour flight covering several Hundreds miles from 6,000-10,000 feet high... should be impressive!!! U ever play around with the rtl SDR's? I just got 2 of them amazing lil cheep things!!!

Never played with one, but when I see the prices, it's tempting. One of the drawbacks of doing radio stuff at work is that I'm often burnt out when I get home, and don't want anything to do with it. That'll probably change with time. I do have a portable short wave radio that I take camping sometimes.

 

[brandonoh777]

Pilots, engineers, ground crew, dispatchers etc have to have some formal education in the use of their radios on VHF Airband - all pilots and quite a few ex flight engineers have an FRTO licence built in to their qualifications. The pilot-to-pilot chat frequencies are strictly unofficial (123.45 etc) and if you missed a call because you were not on the correct frequency you could be in deep doo-doo. An unauthorised user of an airband frequency would be in it even deeper and could lead to massive fines and confiscation of ALL your gear. The FAA and the FCC take a dim view of "interfering with the operations of an aircraft in flight" even if you are a pilot. You will still be an unlicensed person operating an unauthorised unlicensed ground station.

u may be leagely correct...but i can tell u i fly for a living and several times a week and i can tell u its a common thing..espsually late at night!!! thats why u monoter the other freq modern audio panels u can do this easely with and the garmin ones have the digital play back (kinda a DVR) for live radio...u can press a button and go back and hear so many sec... yes it may be technicaly looked down apone by the powers that be but no one said i was going to have a 30 mins conversation here were talking a few mins.. hell i even heard one guy late at night play the bud light real men of genious (discount airline pilot guy) on the 21.5 emergiency freq!!!!

 

[brandonoh777]

The technician license test is fairly easy. If you are already building antennas and putting coax in, it sounds like you are well ahead of many.
For the HF band, you'll need a dedicated antenna to transmit. Not sure what would work best for you location with limited space, but there is a lot of stuff out there. Some simple wire antennas might work well, and you might be able to rig something up using your existing poles.

Not sure exactly what the rules are about transmitting on Air VHF, you'd likely want to look up the specific rules to be sure.

Personally, I think you'd have a lot of fun with a basic amateur hand held radio up in the air. Not sure how well it would work in a cockpit, or even if your company would allow it, but being up 10,000 feet should result in some amazing coverage.

im SURE its not offically aloude but i have tuned in the handheld with the rubber duckie antenna and picked up ASOS transmitters from 50-75 miles away at alitutde and those are VERY low power

 

[mmckenna]

I've been on more than a few mountain tops, 8000 feet or more, and had a VHF hand held with me. Pretty easy to talk 150 - 200 miles or more. It's been a long time, but I used to have a 6 meter SSB radio and I'd take that up on top of a mountain and make some fun contacts over a few hundred miles.

 

[brandonoh777]

I've been on more than a few mountain tops, 8000 feet or more, and had a VHF hand held with me. Pretty easy to talk 150 - 200 miles or more. It's been a long time, but I used to have a 6 meter SSB radio and I'd take that up on top of a mountain and make some fun contacts over a few hundred miles.

ohh ya just with this 40-50 foot high ant that I built and some fine tuning on the SDR, I have picked up airliners transmitting from 200-250 miles away....now they were at the flight levels of coarse.....30,000 and up....but still pretty impressive!! On the transmit end of thing my lil icom a-6 says transmit power 5 watts initially and then 1.5 watts.....what's the dif in beginning and continuous? and does this also depend on bat charge somewhat? and is 1.5 watts enough to hit an airplane 50-75 miles away at several 1000 feet...I think most aircraft panel mounted radios transmit 5-10 or so....or is it more about antenna design and turning so there is little reflected power?

 

[mmckenna]

ohh ya just with this 40-50 foot high ant that I built and some fine tuning on the SDR, I have picked up airliners transmitting from 200-250 miles away....now they were at the flight levels of coarse.....30,000 and up....but still pretty impressive!! On the transmit end of thing my lil icom a-6 says transmit power 5 watts initially and then 1.5 watts.....what's the dif in beginning and continuous? and does this also depend on bat charge somewhat? and is 1.5 watts enough to hit an airplane 50-75 miles away at several 1000 feet...I think most aircraft panel mounted radios transmit 5-10 or so....or is it more about antenna design and turning so there is little reflected power?

I've got an ADS-B receiver at about 850 feet above sea level. I can get aircraft 270 miles out when they are at about 35,000 feet. Every now and then I get stuff 300+ out, but I suspect they are much higher. I see some of the smaller private jets running 45,000 or so, so maybe it's one of them. Pretty amazing.

The aircraft VHF band uses AM, so the power level is measured differently. Modulation changes the power output, to put it simply. Dead key, no audio, 1.5 watts sound about right. make some noise and it'll jump up higher.

Putting a VHF antenna on the belly of a aircraft with a big ground plane around it makes a big improvement. Flying up that high makes it possible to talk several hundred miles with only a few watts. Altitude and a good antenna are amazing things.