Need help please

[cjl_72]

Quick rundown. 2 handheld scanners with taps and a splitter into desktop wimdows 10..

Handheld 1 on 148.562 is 100% decode and sounds clear and crisp if i turn it up.

Handheld 2 on 148.637 is around 40% and when turned up can hear other static etc as well.

Swap codes in scanners or swap splitter ends makes no difference. Seems to be the frequency??

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[jkl090]

are they both transmitted from the same place?

[jkl090]

And isnt the freq supposed to be 148.6375?

[cjl_72]

And isnt the freq supposed to be 148.6375?

It is yes but the handheld scanners won't allow the last 5 on either so set st 148.637 and 148.562

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[cjl_72]

are they both transmitted from the same place?

unsure where it comes from... maybe the university hospital ? I am located in labrador

[jkl090]

Oh right - Not sure if it will make a difference but maybe try 148.648 instead?

[VK3RX]

Handheld scanners usually don't do well with outside antennas. Their sensitivity is matched to the short flexible types supplied, so outside antennas can cause overload and intermodulation from strong nearby transmitters.

So something could be causing you interference or reduced sensitivity on 148.6375MHz.

As to where the transmitters are located, try this:

• go here: https://web.acma.gov.au/rrl/assignment_range.search
• enter your location e.g. Labrador in the "From location/site" field and pick any site that comes up in the area;
• enter a radius e.g. 15km;
• enter a low and high frequency range e.g. 148.000 MHz to 150.000 MHz (don't overlook toggling the field to "MHz");
• ignore the authorisation dates, and hit "Submit".

[cjl_72]

Handheld scanners usually don't do well with outside antennas. Their sensitivity is matched to the short flexible types supplied, so outside antennas can cause overload and intermodulation from strong nearby transmitters.

So something could be causing you interference or reduced sensitivity on 148.6375MHz.

As to where the transmitters are located, try this:

• go here: https://web.acma.gov.au/rrl/assignment_range.search
• enter your location e.g. Labrador in the "From location/site" field and pick any site that comes up in the area;
• enter a radius e.g. 15km;
• enter a low and high frequency range e.g. 148.000 MHz to 150.000 MHz (don't overlook toggling the field to "MHz");
• ignore the authorisation dates, and hit "Submit".

This is the 2 frequencies i use... both frequencies are at hospital and sports centre.. 1 site is no more than 2kms away north and the other is 4km south.... and other pic is the aerial i bought and new 15m cable... to splitter from dave

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[VK3RX]

Hmm ...

Those two frequencies are very close together, transmitters only 2-3km away from you, each radiating 500 Watts EIRP and you are using a 3db gain antenna, and quite a few other pagers within 10km - it's not surprising you are having a problem. I also note that the same frequencies are used by the same provider at two different sites in proximity, so there may be some interaction at your end with the two sites.

If it has the facility, you could try turning attenuation on in the scanner having the problem. Alternatively connect the flexible antenna that came with it and see what the results are.

[cjl_72]

Hmm ...

Those two frequencies are very close together, transmitters only 2-3km away from you, each radiating 500 Watts EIRP and you are using a 3db gain antenna, and quite a few other pagers within 10km - it's not surprising you are having a problem. I also note that the same frequencies are used by the same provider at two different sites in proximity, so there may be some interaction at your end with the two sites.

If it has the facility, you could try turning attenuation on in the scanner having the problem. Alternatively connect the flexible antenna that came with it and see what the results are.

I have no idea about any of this. I spoke to a radio communications company explaining what i have and need to achieve and this is the antenna i was told to get. Any recommendations on antenna or a way to fix this issue?

My monitoring ot has shown that...

At 148.5625 i get 100% with roof antenna then 98% with rubber stubby antenna.

At 148.6375 i get 33% with roof antenna then up to 50% with stubby rubber antenna.

If that info helps

[VK3RX]

The fact that you get better decoding of 148.6375MHz by using the stubby rubber antenna would seem to confirm that particular scanner is getting overloaded by a signal or signals when connected to an external antenna.

Have a look in that scanner's user manual for an ATT/attenuator function able to be turned on or off. If it has that function, turn it on when connected to the external antenna and see how that goes.

What the attenuator function does is put some resistance in line between the scanner's antenna socket and it's receiver stage front end, to reduce the level of signals.

See the article link below, where an adjustable 1k potentiometer is put in line between the antenna and antenna input of a receiver. For the feed to that particular scanner, you could do the same inside your splitter. Alternatively you could make up a short length of coaxial cable with a BNC plug one end and BNC socket the other (if your splitter and scanner use BNCs), and put a 1k resistor in line with the centre conductor. The potentiometer method would be best though, because you can adjust the pot. to the point where the interference disappears.

http://www.qsl.net/pa2ohh/09yachtboy.htm

[Scannersplitterguy]

attenuator.JPG

You could try this ready-made 20dB variable attenuator. About $20 on ebay.
It would go between the antenna cable and the input to the splitter.

http://www.ebay.com.au/itm/Konig-Variab ... 1438.l2649

[cjl_72]

attenuator.JPG

You could try this ready-made 20dB variable attenuator. About $20 on ebay.
It would go between the antenna cable and the input to the splitter.

http://www.ebay.com.au/itm/Konig-Variab ... 1438.l2649

Like this?

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[Scannersplitterguy]

Even better, if you can get one locally.
Just remember to buy a F-F joiner as shown in the pic I posted above. I can't see it on the Jaycar website.

[cjl_72]

Even better, if you can get one locally.
Just remember to buy a F-F joiner as shown in the pic I posted above. I can't see it on the Jaycar website.

All done and no difference that i can see... put between antenna on roof and input on splitter right. 148.6375 rarely seems to get alpha just bs as per pic... attenuator is set halfway atm

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[Scannersplitterguy]

What happens if you swap frequencies on each scanner? Does the same problem occur?

[cjl_72]

What happens if you swap frequencies on each scanner? Does the same problem occur?

normally yes.... but tonight i swapped frequencies on the scanners and was getting 92% on .6375 and crap on .5625.... totally bizarre... now same old 100% and clear on .5625 and crap on .6375 as usual

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[Scannersplitterguy]

I'm out of ideas
Sorry....

[cjl_72]

I'm out of ideas
Sorry....

On 5625 when 100% it is on earphone 1.... if i move to another one it drops bad.... if i have 2 instances of same saved as 1 and 2 do any setting need to be changed or anything?

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[cjl_72]

I'm out of ideas
Sorry....

After a long night i have seen that soundcard configuration settings mean a lot.. get 100% on .5625 as earphone 1 and discriminator 2. Others arent too good....so have now set. 5625 as earphone 1 and .6375 as discriminator 2... will run today a few hrs then swap them.and will see if i can get .6375 to get any better then its 40%...

Bit at least i am.ironimg out the bugs

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