[Premium-Rx] Receive Multicoupler

Adam Harriman adam at sagrad.com
Wed Mar 25 09:09:02 EDT 2009 

Team,

Keep in mind in the range of 3-30MHz thermal noise is typically 20-30dB
below the (natural) noise in the band if you have an efficient antenna.
Noise figures in the HF bands are not as important as you may think if you
have an antenna system that is performing well. If you find noise figure
improves your RX performance you should immediately improve your antenna
system because you have a system problem on your hands.  

My work experience is based on a system of 300 premium radios located at 12
sites scanning the noise and reception of commercial signals over a 5-10
year period. I was the RF system designer for this project. Noise figure and
its cost was a prime issue with cost in this system so we completed a number
of studies. 

While the noise analysis below is valid, it has been my experience that it
is best applied above 50MHz.  

Adam
 

-----Original Message-----
From: premium-rx-bounces at mailman.qth.net
[mailto:premium-rx-bounces at mailman.qth.net] On Behalf Of Nick Vafiadis
Sent: Wednesday, March 25, 2009 8:17 AM
To: 'premium-rx at mailman.qth.net'
Subject: Re: [Premium-Rx] Receive Multicoupler

Paul

> This might be a major issue with weak signals on quiet bands.

Noise figure of 10dB min Typical  9 dB

Thermal noise in 1Hz is -174dBm
Add 10xlog(BW) = 10xlog(1000) = 30dB
Add Noise figure = 10dB

So -174+30+10 =   -134dBm  1KHz Bandwidth (BW)

The Multicouplers are designed to work on large rhombic antenna farms
with The antenna providing some gain


On 25 Mar 2009, at 08:38, Clemens Paul wrote:

>> Input IP3  min  +42dBm typical  > +43 dBm
>> Input IP2  min  +90dBm  typical > +100dBm
>
> These are real excellent numbers,particularly the IP2
> which is often underestimated in its importance.
> For use in central europe this is a must.
>
>> Noise figure of 10dB  min
>
> As the gain is 0dB this would mean a loss in system (rx + coupler)  
> sensitivity of 10dB
> as 10dB noise are added to the received signal.
> This might be a major issue with weak signals on quiet bands.
> Is it really 10dB?
>
> 73
> Clemens
> DL4RAJ
>
>
> ----- Original Message -----
> From: "Nick Vafiadis" <nick.v at commsaudit.com>
> To: <premium-rx at mailman.qth.net>
> Sent: Tuesday, March 24, 2009 11:29 PM
> Subject: Re: [Premium-Rx] Receive Multicoupler
>
>
> For  Receive Multicoupler  CA3035B 1 Input 8 Outputs
>
> Noise figure of 10dB  min
> Input IP3  min  +42dBm typical  > +43 dBm
> Input IP2  min  +90dBm  typical > +100dBm
> Gain 0dB ± 1.5dB
>
> We some times have second hand  that we put on the market
>
> Nick Vafiadis
> www.commsaudit.com
>
> On 24 Mar 2009, at 19:44, Warren Ziegler wrote:
>
>>
>>
>>
>> Hi Steve,
>>
>>      Thanks for the info, I did check out the Stridsberg units but
>> the IP2 and IP3 are at least 10dBm less than the RF Tech coupler.
>> I'm afraid I live in such a heavily rf polluted environment that the
>> Stridsberg's won't hold up.
>>
>> 73 Warren K2ORS
>>
>>
>>
>> ----- Original Message ----
>>> From: Stephen Cannon <sugar_bears_home at yahoo.com>
>>> To: premium-rx at mailman.qth.net
>>> Cc: Warren Ziegler <ny2h at yahoo.com>
>>> Sent: Monday, March 23, 2009 9:08:01 PM
>>> Subject: RE: [Premium-Rx] Receive Multicoupler
>>>
>>> Warren,
>>> I use a Stridsberg Engineering Receiver Multicoupler.  They do make/
>>> sell
>>> Passive Multicouplers in the 100 kHz to 500 MHz range (models MC102
>>> and
>>> MC104). http://www.stridsberg.com/prod01.htm
>>>
>>> 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)
>>>
>>> Options: TNC connectors -
>>>
>>> The MCA104M HF Receiver Multicoupler I use is a 4 port Active
>>> Multicoupler
>>> that covers - 500 kHz to 50 MHz.  Take a look at the data sheet at
>>> http://www.stridsberg.com/mca104a.htm.  Stridsberg also makes a 2
>>> port and
>>> an 8 port version of this same Multicoupler, another series for the
>>> VHF/UHF
>>> range, and another one for 800 MHz Service band Monitoring.  The
>>> product I
>>> received was (in my opinion) a first class piece of equipment (much
>>> better
>>> than the pictures).
>>>
>>> Additional questions on Stridsberg Engineering products can be
>>> answered by
>>> email to stridsberg at bellsouth.net or phone (313)861-0660
>>> (Shreveport, LA).
>>> I am not associated with them other than as a satisfied user of  
>>> their
>>> products.
>>>
>>>
>>> Stephen AD7TD
>>>
>>> -----Original Message-----
>>> From: premium-rx-bounces at mailman.qth.net
>>> [mailto:premium-rx-bounces at mailman.qth.net] On Behalf Of Warren
>>> Ziegler
>>> Sent: Monday, March 23, 2009 12:21 PM
>>> To: premium-rx at mailman.qth.net
>>> Subject: [Premium-Rx] Receive Multicoupler
>>>
>>>
>>> Hello the list...
>>>  Anyone know of a good rf receive multicoupler for 100kHz to at
>>> least
>>> 30MHz?
>>> High IP2 and IP3 is important since I live near several 50kW MW BC
>>> stations.
>>>
>>> Thanks & 73
>>> Warren K2ORS (formerly NY2H)
>>>
>>>
>>>
>>> ______________________________________________________________
>>> Premium-Rx mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/premium-rx
>>> Help Page: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Premium-Rx at mailman.qth.net
>>> Help Contact eMail:  paul at 8zo.com
>>> Home Page:  http://www.premium-rx.org/
>>
>>
>>
>>
>> ______________________________________________________________
>> Premium-Rx mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/premium-rx
>> Help Page: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Premium-Rx at mailman.qth.net
>> Help Contact eMail:  paul at 8zo.com
>> Home Page:  http://www.premium-rx.org/
>
> ______________________________________________________________
> Premium-Rx mailing list
> Home: http://mailman.qth.net/mailman/listinfo/premium-rx
> Help Page: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Premium-Rx at mailman.qth.net
> Help Contact eMail:  paul at 8zo.com
> Home Page:  http://www.premium-rx.org/
>
>
>
----------------------------------------------------------------------------
----
>
>
>
> No virus found in this incoming message.
> Checked by AVG - www.avg.com
> Version: 8.0.238 / Virus Database: 270.11.26/2020 - Release Date:  
> 03/24/09 09:19:00
>
> ______________________________________________________________
> Premium-Rx mailing list
> Home: http://mailman.qth.net/mailman/listinfo/premium-rx
> Help Page: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Premium-Rx at mailman.qth.net
> Help Contact eMail:  paul at 8zo.com
> Home Page:  http://www.premium-rx.org/

______________________________________________________________
Premium-Rx mailing list
Home: http://mailman.qth.net/mailman/listinfo/premium-rx
Help Page: http://mailman.qth.net/mmfaq.htm
Post: mailto:Premium-Rx at mailman.qth.net
Help Contact eMail:  paul at 8zo.com
Home Page:  http://www.premium-rx.org/

More information about the Premium-Rx mailing list