Topics

antenna splitter ?


Robert Harmon <k6uj@...>
 

I want to connect my SDRPLAY RSP1A to the IN/OUT receive antenna connections on my yaesu FT-2000.  What do you guys use for a splitter on your radio with IN/OUT receive connections?  Dumb question, but why not just use a coax T ?  

Bob
K6UJ


KD2OM
 

A splitter gives you isolation between the two outputs and the input as well as keeps the impedance at 50 ohms over the frequency range of the splitter. You will get a 3db loss with a splitter. You can build one with 3 resistors or use a transformer. For HF losses and impedance mismatches are not particularly critical. There are plenty of designs on the net.

Steve KD2OM


On May 25, 2018, at 19:06, Robert Harmon <k6uj@...> wrote:

I want to connect my SDRPLAY RSP1A to the IN/OUT receive antenna connections on my yaesu FT-2000.  What do you guys use for a splitter on your radio with IN/OUT receive connections?  Dumb question, but why not just use a coax T ?  

Bob
K6UJ


Robert Harmon <k6uj@...>
 

Steve,

OK, that answers the question about using a  coax T.   I will pursue a splitter.

thanks,
Bob
K6UJ



From: KD2OM <steve@...>
To: main@SDR-Radio.groups.io
Sent: Friday, May 25, 2018 4:13 PM
Subject: Re: [SDR-Radio] antenna splitter ?

A splitter gives you isolation between the two outputs and the input as well as keeps the impedance at 50 ohms over the frequency range of the splitter. You will get a 3db loss with a splitter. You can build one with 3 resistors or use a transformer. For HF losses and impedance mismatches are not particularly critical. There are plenty of designs on the net.

Steve KD2OM


On May 25, 2018, at 19:06, Robert Harmon <k6uj@...> wrote:

I want to connect my SDRPLAY RSP1A to the IN/OUT receive antenna connections on my yaesu FT-2000.  What do you guys use for a splitter on your radio with IN/OUT receive connections?  Dumb question, but why not just use a coax T ?  

Bob
K6UJ



Kriss Kliegle KA1GJU
 

You can use a coax Tee, if you can get over the 3.5 dB loss. 3.5 dB is roughly 1/2 an S unit (hardly noticeable).
I used to run all my SDR rigs (SDRC Servers) on BNC Tee's. But since I now have more than 2 rigs per antenna, I've been buying the active multicouplers. So now I can run 4 SDR's maximum per antenna.
Also, there will be some other induced losses using just a Tee,

These are what I've been using:
http://www.stridsberg.com/prod01.htm

For some 'light' reading....
http://www.radio-electronics.com/info/rf-technology-design/coupler-combiner-splitter/rf-splitter-combiner-basics.php

73 Kriss KA1GJU


Jorge Diez - CX6VM
 

here you have a great product from KD9SV, now selling at DXE


73,
Jorge
CX6VM/CW5W

2018-05-25 20:19 GMT-03:00 Kriss Kliegle <kliegle@...>:

You can use a coax Tee, if you can get over the 3.5 dB loss. 3.5 dB is roughly 1/2 an S unit (hardly noticeable).
I used to run all my SDR rigs (SDRC Servers) on BNC Tee's. But since I now have more than 2 rigs per antenna, I've been buying the active multicouplers. So now I can run 4 SDR's maximum per antenna.
Also, there will be some other induced losses using just a Tee,

These are what I've been using:
http://www.stridsberg.com/prod01.htm

For some 'light' reading....
http://www.radio-electronics.com/info/rf-technology-design/coupler-combiner-splitter/rf-splitter-combiner-basics.php

73 Kriss KA1GJU




--
73,
Jorge
CX6VM/CW5W


Jorge Diez - CX6VM
 

here you have a great product from KD9SV, now selling at DXE


73,
Jorge
CX6VM/CW5W


2018-05-25 20:19 GMT-03:00 Kriss Kliegle <kliegle@...>:

You can use a coax Tee, if you can get over the 3.5 dB loss. 3.5 dB is roughly 1/2 an S unit (hardly noticeable).
I used to run all my SDR rigs (SDRC Servers) on BNC Tee's. But since I now have more than 2 rigs per antenna, I've been buying the active multicouplers. So now I can run 4 SDR's maximum per antenna.
Also, there will be some other induced losses using just a Tee,

These are what I've been using:
http://www.stridsberg.com/prod01.htm

For some 'light' reading....
http://www.radio-electronics.com/info/rf-technology-design/coupler-combiner-splitter/rf-splitter-combiner-basics.php

73 Kriss KA1GJU




--
73,
Jorge
CX6VM/CW5W


Robert Harmon <k6uj@...>
 

Kriss,

Thanks for the info.   I looked at one of the CATV splitters which have F connectors which I could adapt to BNC, but they also show about 3.5 dB loss.  Too bad, I thought here is a cheap easy splitter, haha. 

Bob
K6UJ



From: Kriss Kliegle <kliegle@...>
To: main@SDR-Radio.groups.io
Sent: Friday, May 25, 2018 4:19 PM
Subject: Re: [SDR-Radio] antenna splitter ?

You can use a coax Tee, if you can get over the 3.5 dB loss. 3.5 dB is roughly 1/2 an S unit (hardly noticeable).
I used to run all my SDR rigs (SDRC Servers) on BNC Tee's. But since I now have more than 2 rigs per antenna, I've been buying the active multicouplers. So now I can run 4 SDR's maximum per antenna.
Also, there will be some other induced losses using just a Tee,

These are what I've been using:
http://www.stridsberg.com/prod01.htm

For some 'light' reading....
http://www.radio-electronics.com/info/rf-technology-design/coupler-combiner-splitter/rf-splitter-combiner-basics.php

73 Kriss KA1GJU



Robert Harmon <k6uj@...>
 

Jorge,

Nice !   I see they have it in either F connector or BNC connector.  

thanks for the info

Bob
K6UJ



From: Jorge Diez - CX6VM <cx6vm.jorge@...>
To: main@sdr-radio.groups.io
Sent: Friday, May 25, 2018 4:27 PM
Subject: Re: [SDR-Radio] antenna splitter ?

here you have a great product from KD9SV, now selling at DXE


73,
Jorge
CX6VM/CW5W


2018-05-25 20:19 GMT-03:00 Kriss Kliegle <kliegle@...>:
You can use a coax Tee, if you can get over the 3.5 dB loss. 3.5 dB is roughly 1/2 an S unit (hardly noticeable).
I used to run all my SDR rigs (SDRC Servers) on BNC Tee's. But since I now have more than 2 rigs per antenna, I've been buying the active multicouplers. So now I can run 4 SDR's maximum per antenna.
Also, there will be some other induced losses using just a Tee,

These are what I've been using:
http://www.stridsberg.com/ prod01.htm

For some 'light' reading....
http://www.radio-electronics. com/info/rf-technology-design/ coupler-combiner-splitter/rf- splitter-combiner-basics.php

73 Kriss KA1GJU



--
73,
Jorge
CX6VM/CW5W



Mike Bott <mike_bott@...>
 

On 05/25/2018 07:26 PM, Jorge Diez - CX6VM wrote:
here you have a great product from KD9SV, now selling at DXE


73,
Jorge
CX6VM/CW5W


"KD9SV Splitter-Combiners cover from 500 kHz through 10 MHz" kinda leaves a bit of the HF spectrum out in the cold.

--
Mike


Robert Harmon <k6uj@...>
 

Good catch Mike.  I didn't notice that.

thanks,
Bob
K6UJ



From: Mike Bott via Groups.Io <mike_bott@...>
To: main@SDR-Radio.groups.io
Sent: Friday, May 25, 2018 5:03 PM
Subject: Re: [SDR-Radio] antenna splitter ?

On 05/25/2018 07:26 PM, Jorge Diez - CX6VM wrote:
here you have a great product from KD9SV, now selling at DXE


73,
Jorge
CX6VM/CW5W


"KD9SV Splitter-Combiners cover from 500 kHz through 10 MHz" kinda leaves a bit of the HF spectrum out in the cold.

--
Mike



Kriss Kliegle KA1GJU
 

https://www.dxengineering.com/search/part-type/hf-receive-antenna-system-devices/receive-antenna-system-device-type/feedline-combiner-spliter/product-line/dx-engineering-2-port-splitter-combiners?autoview=SKU&N=4294950654%2B4294950261&sortby=Default&sortorder=Default

N
ot cheap, but does up to 30 MHz
DX Engineering 2-Port Splitter-Combiners are receive signal-level RF devices that operate from 300 kHz to 30 MHz, available in 50 ohm and 75 ohm versions. They are typically used to split one RF signal to properly feed two receivers, or the receive antenna inputs of one transceiver and one separate receiver. They also properly combine two receiving antennas in phase, such as Beverage antennas, to form a phased receive array.

Important features of the DX Engineering 2-Port Splitter-Combiner:
* Available for 50 ohm and 75 ohm systems
* Broad, 300 kHz through 30 MHz operating range 
* High quality components
* Isolated ports 
* Metal housing for superior shielding and longer life 
* Reliable side-mount connectors: BNC female for 50 ohm, F female connectors for 75 ohm model
* Economical solution to potential impedance errors that cause losses

73 Kriss KA1GJU


agene
 

I have been using the 2 way antenna splitter described in the following article for about 4 years now and it works really well across all HF freqs.


Regards, Mike Simpson
Penrith, NSW, Australia
http://www.rstools.info


Mike Bott <mike_bott@...>
 

One of these days, I want to check out one of the "passive" multicouplers found at the bottom of this page: http://www.stridsberg.com/prod01.htm

--
Mike


On 05/25/2018 08:17 PM, Robert Harmon wrote:
Good catch Mike.  I didn't notice that.

thanks,
Bob
K6UJ



From: Mike Bott via Groups.Io <mike_bott@...>
To: main@SDR-Radio.groups.io
Sent: Friday, May 25, 2018 5:03 PM
Subject: Re: [SDR-Radio] antenna splitter ?

On 05/25/2018 07:26 PM, Jorge Diez - CX6VM wrote:
here you have a great product from KD9SV, now selling at DXE


73,
Jorge
CX6VM/CW5W


"KD9SV Splitter-Combiners cover from 500 kHz through 10 MHz" kinda leaves a bit of the HF spectrum out in the cold.

--
Mike




Robert Harmon <k6uj@...>
 

Mike,

Looks like really good units.  Need to look over the details more but the first thing I noticed was "no signal loss to the output ports"  Nice !

Bob
K6UJ



From: Mike Bott via Groups.Io <mike_bott@...>
To: main@SDR-Radio.groups.io
Sent: Friday, May 25, 2018 5:49 PM
Subject: Re: [SDR-Radio] antenna splitter ?

One of these days, I want to check out one of the "passive" multicouplers found at the bottom of this page: http://www.stridsberg.com/prod01.htm

--
Mike


On 05/25/2018 08:17 PM, Robert Harmon wrote:
Good catch Mike.  I didn't notice that.

thanks,
Bob
K6UJ



From: Mike Bott via Groups.Io <mike_bott@...>
To: main@SDR-Radio.groups.io
Sent: Friday, May 25, 2018 5:03 PM
Subject: Re: [SDR-Radio] antenna splitter ?

On 05/25/2018 07:26 PM, Jorge Diez - CX6VM wrote:
here you have a great product from KD9SV, now selling at DXE


73,
Jorge
CX6VM/CW5W


"KD9SV Splitter-Combiners cover from 500 kHz through 10 MHz" kinda leaves a bit of the HF spectrum out in the cold.

--
Mike






Kriss Kliegle KA1GJU
 
Edited

Yes, because there is just enough amplification to overcome the loss 3.5dB per output. An 8 port multicoupler would have 10.5 dB loss (just less than 2 S units) without the use of an active amplifier. Signals less than an S-7 would be noticeably weaker, and if you had a high noise floor of S-5... not readable.

As for the passive ones Mike,

Common Specifications - Passive
Nominal Impedance:  50 Ohms
Port-To-Port Isolation:  22 dB (min)
                                 25 dB (typical)

Phase (input/output):  Zero degree
Coupler Gain/Loss:  -3.5dB (MC102/202)
                           :  -7dB   (MC104/204)
Case:  Die-cast aluminum, black powder coat
Mechanical:  4-3/8 X 2-3/8 X 1-1/4 Inches (L W H)



I got the idea and info from Simon's website, http://www.sdr-radio.com/Radios


73 Kriss KA1GJU


Kriss Kliegle KA1GJU
 

I stand corrected, post edited.
Tnx!

Public Math is always dangerous!

73 Kriss KA1GJU


Robert Harmon <k6uj@...>
 

One common denominator I see with any of the 2 port splitters, Mini Circuits, the DX Engineering unit, etc is that you will have around 3 db loss.  Can't get away from that.  I guess the best thing to do is get one with good specs on isolation and go with it. 

Bob
K6UJ


From: Kriss Kliegle <kliegle@...>
To: main@SDR-Radio.groups.io
Sent: Friday, May 25, 2018 7:49 PM
Subject: Re: [SDR-Radio] antenna splitter ?

I stand corrected, post edited.
Tnx!

Public Math is always dangerous!

73 Kriss KA1GJU



HF Seattle
 

    Depending on how much you would like to spend, and how many ways you need to spilt, here are my two cents.  I have used many commercial HF multicouplers at commercial HF RX sites and this has been my findings: The first thing is you will need very high port to port isolation or you will see the LO Leakage from other radios.  One of the wonderful things about the SDR-Radio software is that it allows one to see the noise floor so LO noise is much more perceivable than it was pre SDR days, unless you had a spectrum analyzer.  The best combo I have found that outperforms most if not all Commercial units is a Mini circuits  ZSC-8-1+.  This will be a 8 way split with 9.3 db of loss at 60 MHz and up to 42 db of isolation! If you can use a Pre amp with a very High IP3 then place pads after the preamp for max SNR or try to match your NF without the splitter. Depending on how close you are to FM or AM station you might need to use a bandstop filter.  Now, if you only want to go 2 way spliter, you will have the 3db split loss plus a little IL. Keep in mind 3 db is only half of a S meter unit, I think you would be fine without a splitter.  If you would like to use more than 2 way then I would look into a pre amp.  Pre amps on HF have somewhat of a bad name mostly because of improper use or false expectations; but they do work very well and are  used around the world on HF RX systems, you just need to spend some  time with them and you will need to pad the output down.  it is very easy to do with SDR-Radio software. 


HF Seattle
 

Whoops I for got to mention about "Double 3 way" The proper name is resistive splitter they have double the loss so a two way will have 6db of loss and poor isolation around 6db they can be found on ebay stay away from them for you application.  google this  ZFRSC-2050  for the spec sheet again do not get this model just look at the difference form the ZSC 2.     The post from KA1GJU is spot on.


Ulrich C. Thiess | ZOOMsoft GmbH
 

I use professional equipment from mini circuits. They have man splitter. I use ZMSC-2-2 https://www.minicircuits.com/WebStore/dashboard.html?model=ZMSC-2-2 it works from 0-60MHz and above. Unit Price 59,95 US$.

 

There are many more models.

 

I use an ICOM IC 7610 and put the antenna signal thru the RX Antenna Out and In Ports. So if I switched my ICOM IC-7610 on, the SDRPlay works. The Computer is attached to the computer with the help of omnirig. If I switch to TX the RX ports are disabled,

 

73 de Ulrich

 

Von: <main@SDR-Radio.groups.io> im Auftrag von HF Seattle <bradleyforker@...>
Antworten an: "main@SDR-Radio.groups.io" <main@SDR-Radio.groups.io>
Datum: Samstag, 26. Mai 2018 um 05:59
An: "main@SDR-Radio.groups.io" <main@SDR-Radio.groups.io>
Betreff: Re: [SDR-Radio] antenna splitter ?

 

Whoops I for got to mention about "Double 3 way" The proper name is resistive splitter they have double the loss so a two way will have 6db of loss and poor isolation around 6db they can be found on ebay stay away from them for you application.  google this  ZFRSC-2050  for the spec sheet again do not get this model just look at the difference form the ZSC 2.     The post from KA1GJU is spot on.