New antenna help please

[Duramaxman]

I just bought a "Tuned Yagi" antenna, and I know they are directional. Well how am i suppose to know that Ive got it pointed exactly where I need it. Is it a lon/lat thing or what? My problem is I have mountains to overcome, so do i just point it in the general direction? I have Pro106 with 50ft Rg6, THANKS!

 

[popnokick]

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There are three things you'll need to know:
1 - Which end of your Yagi is supposed to be pointed at the signal source
2 - Whether and how to mount your Yagi for vertically polarized signals (most things you'll receive on a scanner are vertically polarized
3 - The direction from your location to your signal source (Google Earth can help with this)
Members reading this here on RR can help with any/all of the above. Do you need help with 1, 2, and 3 or something else?
A comment on #3: keep in mind your signal of interest may arrive from a reflection. Start out by pointing your Yagi directly at the source, but turn it while you are receiving the signal to find possible stronger reflected signal. This is particularly true near mountains.

 

[kb5udf]

Tips

The short answer: Aim the antenna in the direction of the transmitter you want to receive.


Congrats on your purchase. Assuming you are trying to receive something other
than broadcast(ie, FM radio or Television), you should mount your antenna vertically,
such that the elements are in an "up/down" configuration.

Next, you should get a sense of the compass heading between the location
you intend to mount the antenna and the transmitter(s) you want to receive,
and point the antenna in that direction. If you are unfamiliar with this kind of antenna, it is pointed by aiming the shorter elements in the direction you want to receive.

At the end of the day though, it's best to muck around a bit back and forth, checking for the best signal level. The compass heading is just a rough guide, the real criteria is your received signal strength.

As far as terrain obstacles goes, I'll defer to others, but if you have no received signal because
of a mountain for example, this may not be doable. But go for it, you won't really know
what kind of signal you can get until you try.

One other tip, especially at higher frequencies (UHF and above, that is 400mhz and up) try
avoid having the antenna aimed through foliage. Basically, if the antenna were a rifle, you want
it to be "shooting" through clear air and not hitting leaves or other obstructions like rooftops etc.
AIming an antenna through foliage can seriously decrease the received signal.

Good Luck,

JB

 

[W6KRU]

Use the analyze function of your scanner to fine tune the pointing of of the yagi.

Set the ADC Cal extended setting to RSSI: Easier to Read Pro-106/197/PSR500/600 Digital Scanner Manual

Then press the tune button, enter the freq. of interest, and press enter: Easier to Read Pro-106/197/PSR500/600 Digital Scanner Manual

Now you can tweak the direction of the antenna to peak the RSSI level.

If you change the ADC Cal setting back to Off, you can also tweak the direction of the antenna for peak control channel decoding.

 

[kb2vxa]

"My problem is I have mountains to overcome, so do i just point it in the general direction?"

Look at it this way, point it in the direction the signal is coming from, not always the direction of the transmitter. Mountains are usually looked at as blockers, don't forget they're also reflectors. Another thing to consider is the city of license, not always where the transmitter is located.

That's why I never relied on a beam alone, always paired with an omni for signal strength comparison until the source of the signal is located and recorded for reference. That way if you're searching with the beam you won't get confused and wonder if they stopped transmitting or you lost the heading.

 

[Duramaxman]

Thanks DDan, and everyone else but ive read the manual and still not sure on how to go about doin what you said to do. Can you please walk me thru it, freq i want is 460.22500? THANKS!

 

[W6KRU]

Your frequency look like a conventional so you want to peak your RSSI.

Press PGM.
Press FUNC.
Press F3 (GLOB).
Press the down arrow about 11 or 12 times until the cursor is blinking on the ADC Cal line.
Press the right arrow and the value on the right should change from Off to RSSI.
Press F1 (SAVE).
Press TUNE
Press 460.225
Press ENT.
The 4th line down should look like: RSSI: XXX x.xxV
The XXX should be changing numbers. The higher the number the better the signal. With the 800 antenna I get numbers in around 550 on a local weather channel. Point the antenna in the general direction of the tower you want to hear. When they transmit observe the XXX reading. Turn the antenna a little to the left. The next time they transmit see if the XXX number is higher or lower. Then turn the antenna a little to the right. The next time they transmit see if the number is higher or lower. Keep tweaking the antenna from left to right to get the highest reading you can on that XXX number. When you have it set for the highest reading you are done.

 

[reconrider8]

Ive always wondered how you guys set the beams/yagis up so im kinda glad to see what would be better on an 800 system leave the cc open and just keep tweaking until it reads high ow what? sorry if i hijacked the topic.

 

[W6KRU]

Ive always wondered how you guys set the beams/yagis up so im kinda glad to see what would be better on an 800 system leave the cc open and just keep tweaking until it reads high ow what? sorry if i hijacked the topic.

Yeah, same idea but easier because the signal is constantly transmitted. With the control channel you can also tweak the antenna for the best decoding as well.

 

[Duramaxman]

THANKS, Ill let u know as soon as I get it up.

 

[Duramaxman]

Its P25 Digital Kentucky State Police

 

[Duramaxman]

I tried that and jt was showing numbers up and down but it was just static, no talking.

 

[W6KRU]

I tried that and jt was showing numbers up and down but it was just static, no talking.

Yeah, you have to wait for a transmission to get a reading that means anything.

 

[Duramaxman]

I got 546, is that pretty good number?

 

[W6KRU]

I got 546, is that pretty good number?

Yeah that's an OK number, but can you get a better one? Just tweak the antenna around a little and see what you can get.

 

[Duramaxman]

THANKS TO EVERYONE, its picking up better than ever! Now if i can just leave it alone and stop trying to get it a "little bit better" Ill be alright.

 

[popnokick]

Allright - Nice Work! Now please post a pic of your yagi for all of us to see.

 

[Duramaxman]

 

[popnokick]

Your pic and installation are flawless. And thanks for providing a real service to the RR community: A clear photo of a vertically-polarized Yagi mounted on a mast. Early in this thread I was looking for an example pic to point you to, but couldn't find one. But now you've provided a great example.

 

[LtDoc]

The bottom line with any directional antenna is that you point it in the direction you get the best signal from. There are all kinds of "ifs, ands and buts" with that, but that's what it boils down to. With VHF/UHF stuff, start in the general direction of where you think the signal originates, then adjust from there.
- 'Doc