[Milsurplus] RBA RBB RBC receiver multicoupler

Mon Dec 17 12:43:37 EST 2018

Hi

If you spend some “quality time” on the usual auction sites, you can turn 
up the Mini Circuits splitters for pretty reasonable prices. They are tough
to kill so not a big risk to buy used. I have never had one come in and 
have issues. 

I have no problem with winding your own. It’s not that hard to do and the
results are normally quite good. It’s more a matter of “packaged commercial”
vs “the DIY look” …..

Bob

> On Dec 17, 2018, at 12:36 PM, Al Klase <ark at ar88.net> wrote:
> 
> On 12/17/2018 2:05 AM, Jim Whartenby wrote:
>> .... Perhaps Al Klase can comment on this?  He has done a lot of work on MF and HF antenna systems using home made splitters.  See: http://www.skywaves.ar88.net/ANTENNA/antsys.htm <http://www.skywaves.ar88.net/ANTENNA/antsys.htm>Thanks Jim,
> 
> I've been meaning to weigh in on this thread. 
> 
> I think the video distribution amp is a bad bet, especially if you have strong local signals.
> 
> The switch is the simplest solution beyond just feeding all three RX's from the same wire.   No loss, No imtermods.
> 
> I like splitters.  TV/Cable splitters generally aren't much good below about 5 MHz.  You can buy proper splitters from Mini Circuits but they're expensive.  
> Splitters are easy to make, and the same binocular cores and wires can be used to make other useful MAGNETIC COMPONENTS <http://www.skywaves.ar88.net/ANTENNA/N3FRQ_Baluns.pdf>.
> So, order up a dozen BN-73-202's and some #26 low-temp magnet wire from Amidon. <http://www.amidoncorp.com/bn-73-202/>
> 
> For Jeff's application, I'd make two two-way splitters, and feed the HF set from the first unit (-3db), and the LF and MF radios from the second cascaded splitter (-6dB).  Those losses are going to be barely noticeable given the background noise at these frequencies.
> 
> My dissertation on antenna distribution systems is HERE <http://www.skywaves.ar88.net/ANTENNA/antsys.htm#Splitter>.
> 
> Have fun,
> Al
>> 
>> 
>> From: Bob kb8tq <kb8tq at n1k.org> <mailto:kb8tq at n1k.org>
>> To: JEFF CICCONE <kg2bz at comcast.net> <mailto:kg2bz at comcast.net> 
>> Cc: Military Surplus Mail List <milsurplus at mailman.qth.net> <mailto:milsurplus at mailman.qth.net>
>> Sent: Sunday, December 16, 2018 3:25 PM
>> Subject: Re: [Milsurplus] RBA RBB RBC receiver multicoupler
>> 
>> Hi
>> 
>> A 30 db noise figure is considered “pretty quiet” in terms of a video distribution 
>> amplifier. That’s not to say that they all have that sort of noise, but that the one
>> you get could easily be that noisy. In terms of getting to the sort of 6 db or so 
>> NF you probably would want in an antenna distribution setup …. look elsewhere. 
>> 
>> A 4 way power splitter should be pretty easy to find with 6db loss per port. That
>> would likely do better for a coupler than one of the video gizmos and would be
>> at least as cheap.
>> 
>> Bob
>> 
>>> On Dec 16, 2018, at 3:51 PM, JEFF CICCONE <kg2bz at comcast.net <mailto:kg2bz at comcast.net>> wrote:
>>> 
>> 
>> Folks
>> I have been fortunate to have this nice receiver lineup however I am using an 3 position antenna switch to make the connection from my rf bnc antenna patch panel
>> 
>> I saw an article written by a british ham about using an Extron DA2 RGBHV wideband video distribution amp in lieu of rf multicouplers for my 3 navy receivers
>> 
>> http://gm1sxx.blogspot.com/2018/01/the-poor-mans-receiver-multicoupler.html <http://gm1sxx.blogspot.com/2018/01/the-poor-mans-receiver-multicoupler.html>
>> 
>>  Has anyone tried this ?   Those units are always on ebay and are inexpensive. I wonder how well they handle weak signals, nearby transmitters, IMD etc? I oredered one and will let everyone know how it performs
>> 
>> What about using Extron Ultra-Wideband Matrix Switchers for RGB and Stereo Audio as a crossbar switch to route and select multiple receivers to multiple antennas?  I realize they cannot be used for transmitting. 
>> 
>> By the way I echo the comments about the magnificent beast RBC.  Its smooth tuning , its squelch/silencer and noise limiter circuits really work. The audio filter in the sharp mode is great for crowded CW signals. 
>> 
>> Jeff KG2BZ
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> -- 
> Al Klase – N3FRQ
> Jersey City, NJ
> http://www.skywaves.ar88.net/ <http://www.skywaves.ar88.net/>
> 
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