Daytime/Nightime Reception

Oh, I have several GOOD FM receivers, Kent... An ICOM R-7000, Yamaha RX-V1, 2 Nems-Clarke Special Communications Receivers, Hallicrafters SX-62B... I'm not TOO bad off in that respect.. To me, FM DX is more fun & challenging than MW or SW, 'cause you NEVER really know how things are gonna "Stack Up" on any given day... FM DXing truly IS a "Black Art"...

Sandy G said:

Oh, I have several GOOD FM receivers, Kent... An ICOM R-7000, Yamaha RX-V1, 2 Nems-Clarke Special Communications Receivers, Hallicrafters SX-62B... I'm not TOO bad off in that respect.. To me, FM DX is more fun & challenging than MW or SW, 'cause you NEVER really know how things are gonna "Stack Up" on any given day... FM DXing truly IS a "Black Art"...

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Nice have a couple myself. an IC-R7000 along with the TV modulator. Seems when using that it is a sponge while several other otherwise very nice high line Tuners fall short. The Icom is certainly an interesting receiver to use along with some gain antennas and a mast mounted pre-amp.

Hermit

Update:

I added the 5' mast section today. Now the mast is 25' high which is about as far as I dare w/o guy wires. It's secured to the the eave at about the 15' mark. It's actually a little more than I'm comfortable with as I have a pretty good sized VHF-UHF-FM antenna at the top and a small FM omni about 7' below it.

I also cleaned up the connections. There was one that was real corroded. Actually it was full of water. So getting that fixed helped a lot. I was getting better daytime reception than I've got in a good while.

The Terk FM+ arrived too. I tried it in my main rig which is on the big antenna. Not good. The Terk was basically worthless; at least in this location. I'll try it in some other rooms.

So now I'm thinking of trying the Magnum-Dynalab ST-2. If it was installed on top of the 25' mast, it might work pretty well. Would it be even better to connect it to the directional antenna already there or would it be best by itself?

jdmccall said:

I added the 5' mast section today. Now the mast is 25' high which is about as far as I dare w/o guy wires. It's secured to the the eave at about the 15' mark. It's actually a little more than I'm comfortable with as I have a pretty good sized VHF-UHF-FM antenna at the top and a small FM omni about 7' below it.

I also cleaned up the connections. There was one that was real corroded. Actually it was full of water. So getting that fixed helped a lot. I was getting better daytime reception than I've got in a good while.

The Terk FM+ arrived too. I tried it in my main rig which is on the big antenna. Not good. The Terk was basically worthless; at least in this location. I'll try it in some other rooms.

So now I'm thinking of trying the Magnum-Dynalab ST-2. If it was installed on top of the 25' mast, it might work pretty well. Would it be even better to connect it to the directional antenna already there or would it be best by itself?

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As a "DX'er" with a directional antenna and a rotor I don't see any point in defeating the directionality of the setup by splicing-in an omni-directional vertical. sKiZo can speak for himself but when this came up in discussion before his approach was to have an omni-directional pattern but with a little bit of a lobe towards a particular college station. So he has a peculiar goal in mind. I'll let others get into matching, spatial orthogonality, electrical non-orthogonality, the price of tea in China, etc.

Sounds like you're really starting to rock though, that's the main thing, congratulations. Please post some pix so we have some visuals. :thmbsp:

It might be a good idea to be able to switch between an Omni and a directional antenna so the Omni can find everything on the band and the directional antenna can then be set to find it and get the most signal while suppressing signal from other directions. A co-ax switch or a 300 ohm ribbon lead switch would keep one from interfering with the other.

amptramp said:

It might be a good idea to be able to switch between an Omni and a directional antenna so the Omni can find everything on the band and the directional antenna can then be set to find it and get the most signal while suppressing signal from other directions. A co-ax switch or a 300 ohm ribbon lead switch would keep one from interfering with the other.

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If you are using 75 Ohm Coaxial cable you can get a switcher or simple two /three way switch to choose the antenna. If you are using 300 Ohm twin lead you can just use a simple toggle switch just make sure it is a DPDT or Double Pole/Double Throw so you get both halves of the lead in contacting.

Thee are numerous plans to make switches just do a search under Amateur Radio coax switches or 450 Ohm (ladder line) switch and follow the simple directions and since you are worried about RF via transmit it is quite simple to build. I have seen folks even use common light switches to turn on/off a connection. They got some light switches and an electrical box to build it into, attach connectors to suit and there you go.

You can also go the pre-built commercial switches from various manufacturers like MFJ, Alpha delta ( not cheap) and others. I use the cast metal devices since I use them for both transmit and receive but for receive only you aren't concerned with the RF leaking into the transceiver.

If you want to build one and can't seem to locate a set of plans email me and I will try to help you out. (But please do take the time and make an effort to locate it before asking as you will also discover a ton of really cool stuff as well)

One final thing if you are using a directional antenna PLEASE don't couple it to an omni or you basically do 2 things....
1. you defeat the directional or beam antenna narrow beam width and it injects signals from all directions to overload and cover up the weaker desired signal the beam is receiving;
2. When you co-phase or join two or more antennas properly done you increase both gain and other factors. But you also must insure the antennas are similar and their match (VSWR) is reduced to a level that is lowest for the frequencies used and that allows maximum transfer of the signals both in transmit and RECEIVE which is what you put that rascal up to get in the first place..

Now that I mentioned several terms you may or may not understand it might be a good time to read up on Amateur Radio a bit and discover how easy it is to get a license and join the fun. Not only do you get to listen you get to talk to others literally around the world so how cool is that...

Hermit (Licensed Amateur, VE yada yada hi hi)

The pic didn't turn out a swell as I'd hoped but you get the jist of it. The directional is an Antenna Craft...not sure of model off the top of my head, but the beam is in the 7-8 ft. range. The little omni below is an old Radio shack model. it's pretty old and has had some abuse from the local owl population but it's still standing. the down lead is 75 Ohm RG6. It looks like I need to do some strain relief on the top antenna! The big boy is connected to my NAD stereo tuner and the little omni is connected to the Marantz AVR in another room.

jdmccall said:

The pic didn't turn out a swell as I'd hoped but you get the jist of it. The directional is an Antenna Craft...not sure of model off the top of my head, but the beam is in the 7-8 ft. range. The little omni below is an old Radio shack model. it's pretty old and has had some abuse from the local owl population but it's still standing. the down lead is 75 Ohm RG6. It looks like I need to do some strain relief on the top antenna! The big boy is connected to my NAD stereo tuner and the little omni is connected to the Marantz AVR in another room.

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Looks good, I took the liberty of adding it to the antenna pix thread.



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jdmccall said:

The pic didn't turn out a swell as I'd hoped but you get the jist of it. The directional is an Antenna Craft...not sure of model off the top of my head, but the beam is in the 7-8 ft. range. The little omni below is an old Radio shack model. it's pretty old and has had some abuse from the local owl population but it's still standing. the down lead is 75 Ohm RG6. It looks like I need to do some strain relief on the top antenna! The big boy is connected to my NAD stereo tuner and the little omni is connected to the Marantz AVR in another room.

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So you have two different antennas on one mast and each antenna "feeds" a separate receiver's tuner section. No worries then as you aren't combining two different types of antenna and using the combined down linked signals to a single receiver or tuner.

The problem occurs when you take as I mentioned above the combination of a directional antenna and an omnidirectional antenna reception and then try to put both signals together as it will basically defeat the directional antenna's effect. You will get signals but you will also almost certainly experience a lot more multi-pathing and that would not be a good thing.

I use several antennas for general broadcast reception and then again I use several antennas for my Ham activities. Some commercially made and some I home-brewed or built myself either from plans I found or designed from scratch. Over the last 3-4 decades I have had success and of course failures in part but had a learning experience, which lead to later success.


Just this morning I decided to build a vertically polarized Omni FM antenna out of some aluminum I had. I computed the over all total length, the matching portion (in this case a Gamma Match) and then used an antenna analyzer to get the VSWR (Vertical Standing Wave Ratio) down as far as I could. Result was a 15 foot tall antenna with a 1:45:1 VSWR and it looks like a series of telescoping tubes with an "X" at 1/4 of the way down from the top. I could have kept at it till I got close to the magical unobtanium 1:1:1 match reading but for its intended use the match it has was useable and I didn't want to spend time trying for a lower match as it would have gained me enough to warrant the effort since I wasn't using it for transmit too. You should always try to get the best you can but for receive in this case my results were acceptable for now. I know I will fiddle with it at some point as I can't seem to leave well enough alone hi hi.

It is fed with 75 Ohm RG-6 quad core coax. I have it fixed to a wood blind in the back yard to feed the Onkyo receiver in my Ham Shack. It is mounted so the top is about 20 feet from the ground at the furthest point. Took about 2 hours from start to finish and all this to get 1 college Jazz station about 50 miles from me and I am technically over 10-15 miles outside their fringe reception area to boot.
State Long Beach ( Signal Hill CA is the transmitter site's location)

Hermit

Hermit418 said:

Took about 2 hours from start to finish and all this to get 1 college Jazz station about 50 miles from me and I am technically over 10-15 miles outside their fringe reception area to boot.
State Long Beach ( Signal Hill CA is the transmitter site's location)

Hermit

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Pretty good DX if you're a VE. :thmbsp:



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loopstick said:

Pretty good DX if you're a VE. :thmbsp:

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V.E. in USA for Volunteer Examiner.

Extra Class Op.
Hermit

I remember I heard a Pirate once, back in the early 90s."The Voice of Bono", as he called himself. I think it was on Andrew Yoder's program where they gave out frequencies. Anyhow, I sent the guy off a QSL report, told him where I was, etc. He sent back a nice letter-I think he'd gone to school at ETSU ! Small world...