I bought a HomePatrol 2 and a Sirio Antenna SD2000N... what cable and adapters do I need?

CanAm

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So I guess the HP-2 has an SNF-female connector, and the Sirio Antenna SD2000N has a female N connection. So what sort of cable and adapters would be recommended?

Sorry, I've never hooked up a scanner to a "real" antenna before. Thanks for any advice.
 

jonwienke

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The HomePartol has a SMA connector, but comes with a BNC adapter. Get a cable with a N connector on one end, and BNC on the other.
 

CanAm

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Oops, sorry, yes SMA connector. So N-male on one end of the the cable , a BNC-male at the other end of the cable, and use a BNC adopter on the HP2.

Looks like from the other thread I read LMR-400 or RG6.
 

mmckenna

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Looks like from the other thread I read LMR-400 or RG6.
The type of cable you need depends entirely on your frequencies of interest and how long the cable run is.
RG-6 and LMR 400 are popular, but may not be sufficient in very long runs, or maybe overkill in short runs.

Also, finding N connectors for RG-6 can be difficult. Yes, you can find them, but they are not as common as what you'll find for some other cables.

You can order custom cables from several sellers. It's a good idea to get exactly what you need and avoid adapters. Adapters can place strain on the antenna connectors on the rear of the radio. If you end up using LMR-400, it is stiff stuff and can put a lot of stress on the radio. It's common industry practice to use a short jumper of a more flexible cable to make the final connection to your radio if you are using heavy/stiff coax. A short jumper of RG-58 with a male SMA on one end to match your scanner, and a mating connector on the other to match your coax would be a good idea.
 

CanAm

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The type of cable you need depends entirely on your frequencies of interest and how long the cable run is.
RG-6 and LMR 400 are popular, but may not be sufficient in very long runs, or maybe overkill in short runs.

Also, finding N connectors for RG-6 can be difficult. Yes, you can find them, but they are not as common as what you'll find for some other cables.

You can order custom cables from several sellers. It's a good idea to get exactly what you need and avoid adapters. Adapters can place strain on the antenna connectors on the rear of the radio. If you end up using LMR-400, it is stiff stuff and can put a lot of stress on the radio. It's common industry practice to use a short jumper of a more flexible cable to make the final connection to your radio if you are using heavy/stiff coax. A short jumper of RG-58 with a male SMA on one end to match your scanner, and a mating connector on the other to match your coax would be a good idea.
Thank you so much for the advice of a custom cable. And never having done this, I can see a stiff coax cable being a nuisance as a direct connection, especially to something like HomePatrol 2, which is both an expensive scanner but encased in fairly flimsy plastic (I was surprised how seemingly delicate it was compared to my 25-year old Uniden BC 780 XLT, which seems as sturdy as a rock).
 

CanAm

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Here is what I came up with, I attached my antenna to a T-Post, lashed to our second story porch. Right now it is ungrounded, and I know that is Bad.

IMG_20200906_191026029_HDR smaller.jpgThe reception has improved dramatically with the antenna though. I went from 1 NOAA weather station to 3 as a matter of objective measurement, and I am pulling in a lot more of everything else and a lot more clear. This Sirio antenna sure seems well made.
 

Ubbe

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How come that you selected that particular discone antenna? It is a special version to optimize 145MHz for radio amateurs and also work well at the neighbour frequencies around it like the NOAA ones. But it will also trash reception in most other frequencies, like vhf airband, as it interferes with the discones function and the good SWR are only at multiples of that 145MHz frequency.

I would suggest that you try without that top element with the coil in the middle and see how it receives especially in the UHF and 800Mhz bands. Also remember that a discone like that also have more than a 10dB loss at 900MHz from signals at the horizon, as the direction are pointing up in the sky. Sirio's diagram show that the -3dB loob are pointing up in the sky at a 60 degree angle at the 900Mhz band.

That top element makes this discone works more like a GP antenna in the 135-160MHz band, but that might work for you if that frequency band are where you would like to focus your reception.



/Ubbe
 

CanAm

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How come that you selected that particular discone antenna? It is a special version to optimize 145MHz for radio amateurs and also work well at the neighbour frequencies around it like the NOAA ones. But it will also trash reception in most other frequencies, like vhf airband, as it interferes with the discones function and the good SWR are only at multiples of that 145MHz frequency.

I would suggest that you try without that top element with the coil in the middle and see how it receives especially in the UHF and 800Mhz bands. Also remember that a discone like that also have more than a 10dB loss at 900MHz from signals at the horizon, as the direction are pointing up in the sky. Sirio's diagram show that the -3dB loob are pointing up in the sky at a 60 degree angle at the 900Mhz band.

That top element makes this discone works more like a GP antenna in the 135-160MHz band, but that might work for you if that frequency band are where you would like to focus your reception.



/Ubbe
If this was Facebook, I would give you a "heart" for your post. :) That is great information.

I selected this antenna because I vaguely gathered (on my own) I needed an all purpose antenna for a scanner like the Homepatrol-II. And I read some discussion about disconne antennas. Then I went to Amazon and this antenna got good reviews and seemed like what I would need in my novice judgment. From the product description: " This antenna covers the frequency range of 100-2000 MHz and, due to its broadband concept, is suited for scanner and monitoring applications." .

At least, as a positive, I am pretty much not scanning anything over 155 Mhz - pretty much standard police and fire and forest service (since I live right on the tree line of a forest though you can't tell by the picture). But I do see there are some extender and associated frequencies in the 400, 700 and 800 range and I will give some testing without the top element (very easy to unscrew from the antenna body).

You are right about NOAA. I hardly listen to NOAA, but it really did go from one channel only and absolutely nothing else, to three channels as clear as a bell.

The VHF air band performance is there, but I think it pretty much matches what I am getting with my old Uniden BC XLT 710 with just its simple "plug in" antenna in the back. So the airband is nothing special.

In the 150 Mhz range, where I am doing a lot of listening, I would say it was as exponential leap forward. And, maybe, surprsingly, the 40 MHz (California Highway Patrol) is a lot better.
 

Ubbe

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I add one picture from Sirios webpage that shows that a discone at it's lowest frequency acts more like a dipole in the elevation direction and then at UHF starts to tilt the direction upwards but mostly down towards the ground. So a 100MHz-500MHz range seems to be the useable limit for a discone antenna.



/Ubbe
 
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