Shortwave Antenna Combiner

[E-Man]

Interested if anyone has any experience using a Combiner/Splitter on 2 Shortwave Antennas feeding one Receiver.

RF Systems claims:

Extensive
tests by RF Systems show that in 98 % of the cases an increase in signal strength is observed when two​

antennas are used instead of one.

http://www.rf-systems.nl/pdf/sp1.pdf

Anyone have experience with the RF Systems SP-1?

RF Systems SP-1 Splitter and Combiner

Any other Combiner/Splitters with PL-259 connecters without having to homebrew? I have searched but did not find any.

Thanks

 

[E-Man]

I just noticed Universal Radio has a similar unit:

Apex SPL-2 Splitter and Combiner

 

[k9rzz]

For $129 to $149 ???

It's your money but I say DON'T DO IT! There's no magic wand inside that little box.

PM me and I'll custom build one for you for a LOT LESS! I've got the parts on hand.

Do they work? I don't know a whole lot about diversity reception, but you'll have to have your two antennas well spaced apart (many wave lengths) to have any chance. Perhaps if you've got one vertical and one horizontal antenna that might help reduce fading with such a simple setup.

 

[brandon]

You might also look into the ICE splitters
Receive Only Processing Equipment

 

[k9rzz]

The ICE products are much more reasonable. They are well made but note that they use photo jacks (like audio cable) for antenna connections, not SO-239 or BNC connectors. You'll need to outfit your antenna cables to match, or buy adapters to fit (add that into your cost).

 

[Murstech]

If you combine two antennas you may experience some gain. Its the same thing as increasing your antenna length. So two antennas of equal size and performance combined will yield maybe 3db.
The thing is is that the phases of the two combined signals are going to be adding and subtracting and theres no way to control the randomness. signals are going to rise and fall just the same as with a single antenna.
Now.. with true diversity reception two receivers are used and combined in such a manner so that when the signal fades on one antenna the other antenna is able to "take up the slack". A true diversity reception system will decrease fading and selective fading and is far superior than using a combiner to couple two antennas.

 

[jyams]

ICE will custom make whatever connectors you desire

I've been using the ICE splitters for years and you can call them and they will put whatever kind of connectors on them you want. I've had them make several custom splitters for me. I have one of their splitters that uses a power supply for a built-in signal boost. Also use the regular splitter without a power supply and it works great also. Call them. They'll make up whatever you want.

 

[k9rzz]

Just to be clear, simply hooking up two antennas together won't give you 3db of gain. I just wouldn't want anyone to get that notion out of context.

 

[E-Man]

Thanks everyone for the replies.

Here is my situation, years ago when I wired my shack, I ran cable for a Wellbrook Loop and Rotor to my attic. Since then I have added 4 times the insulation and many antenna's. (I will have a better idea, exactly what my options are latter this week/weekend when I venture up in my attic to add a Preamp to my TV Antenna).

Thanks to jyams, I have just acquired 2 Wellbrook Loops, but my concern is, I may not have proper room for both in my attic mounted on rotors, also this would require adding one more rotor cable. In addition, I now have many more SW antenna's than I will probably ever have Receivers for. So I thought a better solution to a switch, would be to mount one, in a N/S position, and the other E/W and use a combiner/splitter to my main receiver?

Jyams, have you tried a splitter on the Wellbrooks?

Unfortunately outside mounting is not an option at this time. What would you guys recommend?

Thanks

 

[k9rzz]

What would you guys recommend?

A switch.

 

[Fast1eddie]

I have been using a passive single input dual output Strideberg product for HF (rx only) and a single input 4 output model for vhf/uhf.

Have never had a problem with multiple receivers (AOR and Icom models), only once or twice did some birdies self generate.

Pricing was extremely reasonable and despite my RF background, I doubt I could build anything close to the quality of a commercial unit.

Got mine from Grove.

 

[Kennrth]

Who’s buying snake oil today. Combining radios and antennas into networks is for convenience nice but almost always decreases performance. The hardware peddlers are at it again. Can’t imagine why. Antenna manufacturers can are no longer allowed to publish their antenna specs in their advertisements in ARRL publications because they lie like a rug. Combining two antennas for better performance not on your life. You would need to buy co phased array designed to work for a narrow band and the combiner comes with it because the transmission lines needs to be co phased also. Buy a quality transmission line switch and be very very happy.
I get a kick out of “ I quote “ – Verified by independent labs.
Yeah who paid them?
Where is the real data for review?
Is it traceable to NIST?
How can you prove they are independent?
Is it repeatable?
Is the device being manufactured and sold identical to the one being tested?
How do you prove that.
Trust me Trust me.
Radio performance is easier to verify

 

[E-Man]

The last 2 days I have tried to call ICE:

Industrial Communication Engineers, LTD.

1-800-423-2666

Strange, nobody home, and no greeting?

I will shoot them an email and see if I get a response.