Cool Discovery

[digitalanalog]

A friend of mine moved out recently and i asked him for the old DISH Network Sat Dish he had on his house and he said, Please take it.

It had the standard Dish Network receiver head on it as well as a Local receiver head on it.

So i thought i would give it a shot and see what happnes when it get's connected to a scanner.

I just left the dish on the ground (facing skyward)and hooked up a rg8 cable to the Local receiver head then connected it to my handheld scanner (BC120XLT) and guess what........It picked up stations approx 60 miles away, i live in a rural area, so i only scan 30-512MHz, and the reception was amazing, and with the dish just laying on the ground, i would imagine putting it up on a mast that it would work even better.

I also hooked the scanner up to the Dishnetwork receiver head but i got NO reception at all.

Just thought i would pass this info on.

I am also planning on using this to mount a freq specific J-pole antenna into the center, and using the dish as an excellent source as a ground plane.

so if you have an old Sat dish laying around or no some one that does......., consider doing some testing with it.................

JUST FYI...............

 

[prcguy]

I ran some RF ingress tests on the same type dish/LNBs a few years ago and arrived at a completely different conclusion. The LNBs for direct to home satellite do not pick up or amplify anything near what we receive on our police scanners, especially when there is no power applied to the LNB, which I assume is the case for the original post. The LNBs are very well shielded being in solid cast metal housings and there specifically designed to NOT pick up anything that would interfere with the block down converted satellite signals in the 950 to 1450MHz for older LNBs and 250 to 2150MHz for some of the newer designs. I monitored the output of a direct to home dish with about 75ft of quad shield coax feeding its receiver (for power only) and spectrum analyzer. Except for test transmissions I was sending from some nearby HF, VHF and UHF amateur and commercial transmitters, nothing was visible on the spectrum analyzer in the 1MHz to 950MHz spectrum. Many scanners have a plastic case and will receive fine without an antenna. A random hunk of coax attached to a dead Dish dish will probably pick up a little more than no antenna on the scanner, but that’s about it.
prcguy

 

[digitalanalog]

Well, it works for me, and i plan on doing some other goovy stuff with it, just to see what happens.

As well, where i live, without an antenna i can't receive anything, i live in a rural area,down in a valley and surrounded by 60-100' tall tree's.

while trying odd things one day, i also found if i put a magmount antenna in my old Steel wheelbarrel, and wheel it around the yard on a long coax,then tilt iton it's side , worked amaingwell,and the magmount antenna never worked at all on it's own and i mentioned where i live.

I try tons of strange things just to see what works.

I think i'll try extending my aluminum ladder and hook coax to it, hey it might work......

I have some pics of some of the home brewed antenna projects i will try and get them posted.

 

[iMONITOR]

I think i'll try extending my aluminum ladder and hook coax to it, hey it might work......

It will work. Any piece of metal will function as an antenna to some degree. Even a coat hanger.

 

[jjudson]

This has got me curious. What would be the result if I took an old dish and mounted a Yagi 800 Mhz antenna in front of it?

 

[LEH]

True on the nearly any piece of metal will work as an antenna.

In the late 70's the 81st TFW at RAF Bentwaters maintenance was on 30.1 MHz and 30.15 MHz. As I was in maintenance and already into scanning, I got a four channel multi-band hand held crystal controlled scanner that picked up VHF-LO. When I was at home, I took about 100 feet of aircraft grounding wire (salvaged from the trash), ran it across a beam in the bedroom (old [1566] English house) and out a window (sort of inverted L). I was able to get the base just fine (along with a lot of stuff on the skip from the US).

 

[unitcharlie]

I try tons of strange things just to see what works.

This is the second time this week I have used this quote....
"If it is stupid but works it isn't stupid."
-Murphy's Laws of War
Some of the neighbors see me on the back porch trying to find the sweet spot for a trunked site and then the antenna is mounted to a deck chair or the top of the grill... or tied to some twine that has been thrown over a tree bracnh to get enough decode to use Trunker....

 

[wizardmj]

cool discovery

Now I am very curious as to use a none used sat dish for radio reception. If I decide to hook it up to a scanner via the cable where would I get a coax to bnc adapter ? Its just sittin there so I might just figure out a better use for it. The wife will make me throw it away or use it for a flower pot LOL... Cant have that:lol:

 

[poltergeisty]

I think i'll try extending my aluminum ladder and hook coax to it, hey it might work......

Unless it touches the ground. :lol: Don't know if it would matter on receive though.

 

[N_Jay]

Random antenna produce random results.
Random results occasionally are perceived as "successful test"

These misconceptions build superstitions and myths that get in the way of true learning.

Go have fun, but you won't "discover" or "learn" much this way.

 

[prcguy]

If you simply hook up the unused dish to your scanner it will have similar results as connecting the same coax to a 75ohm load at the end. Any reception will be from leakage through the coax, which I would consider a less than desirable antenna.
prcguy

 

[sjcscanner]

let me clarify here... if i take a long metal pipe, and simply wrap coax around it and plug it in to my scanner it will give me reception?

 

[N4JNW]

His post states he didn't recive off the LNB. His recpetion is coming from the local antenna which is in the dish.

Hooking your coax to the LNB will be useless. The frequencies to where it becomes active are well above 1 ghz. If you cut the front of the LNB off, you'll see a small wire inside the "cone". That is the antenna. It's about 1/2" tall. I demolished one one time just to see what was inside.

 

[prcguy]

I missed the "local receiver head" part, sorry. If its the goofy hairpin folded dipole TV antenna that clips to the top of the dish or something similar with a diplexer, then there is an antenna that would pick up something on a scanner.
The pickup "antenna" inside the LNB are traces on the circuit board centered to the feed and they will be about .2" long and 45deg apart. A wire or stepped metal fin or plastic card inside the throat of the horn is to force the feed into a circular pol rather than linear pol.
prcguy

 

[prcguy]

Yes, more so than no cable connected to your scanner and the reception (if you call it that) will improve at higher frequencies. Many types braided coax have shielding effectiveness of maybe 40 to 50dB, so strong signals will leak through, even with a termination at the end of the cable. Most scanners have plastic cases and if you remove the antenna it will still pick up lots of stuff. I can't keep my local PD out of my scanner with no antenna unless I find a good quality screen room.
prcguy

let me clarify here... if i take a long metal pipe, and simply wrap coax around it and plug it in to my scanner it will give me reception?