[Premium-Rx] RE: Premium-Rx digest, Vol 1 #9 - 4 msgs

AKnott at WTD71.de AKnott at WTD71.de
Mon Nov 11 22:58:00 EST 2002


I owned a multicoupler which was manufactured in Hungaria during the former
eastern block period by the factory ML ("mechanica laboratorium" or the
like), a company which produced many items for their (the eastern block)
military communication. I still own the manual. The coupler had a highpass
filter (against strong signals from local MW-stations) and a lowpass filter
(against strong signals from local VHF- or FM-stations) at the input. Then a
limiter and a preamp followed by a pushpull power amp with those hard to get
2N5160 (the power amp may be substituted by a video power amp, e.g. from
ELANTEC) wich drove a resistive divider. I am not shure: there were between
9 and 12 outputs. I can give the manual to a local copy shop here, if anyone
is interested and will pay the money for shipping. Please keep in mind: the
manual is written in hungarian language! But it is not too difficult to find
out what you want to find out, Hi.

With greetings from Germany

Andreé Knott DD3LY


> -----Ursprüngliche Nachricht-----
> Von:	premium-rx-request at ml.skirrow.org
> [SMTP:premium-rx-request at ml.skirrow.org]
> Gesendet am:	Montag, 11. November 2002 21:01
> An:	premium-rx at ml.skirrow.org
> Betreff:	Premium-Rx digest, Vol 1 #9 - 4 msgs
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> Today's Topics:
> 
>    1. RE: Antenna Couplers (Morris Odell)
>    2. SV: [Premium-Rx] Antenna Couplers (Karl-Arne.A.Markstrom at telia.se)
>    3. RE: Antenna Couplers (Carcia, Frank A.           HS)
>    4. Re: Antenna Couplers (Aidehua at aol.com)
> 
> --__--__--
> 
> Message: 1
> From: Morris Odell <MorrisO at vifp.monash.edu.au>
> To: "'James C. Garland'" <4cx250b at muohio.edu>,
>         "'premium-rx at ml.skirrow.org'" <premium-rx at ml.skirrow.org>
> Subject: RE: [Premium-Rx] Antenna Couplers
> Date: Mon, 11 Nov 2002 09:15:52 +1100
> 
> Jim Garland wrote:
> 
> > Does anyone have a circuit diagram of an active multicoupler? 
> > I'd like try 
> > and homebrew one, and don't want to reinvent the wheel.
> > Thanks,
> 
> I use an 8 channel one I built a few years back which is quite simple. It
> uses a "Norton" transformer coupled feedback amp with a 2N5109, feeding a
> simple resistive divider chain. The overall loss is about 3 dB. Ahead of
> it
> I have a "QRN squasher" noise cancelling circuit which picks up the
> (considerable) local crap here on a small wire antenna and allows me to
> cancel it in the main signal chain.
> 
> There are lots of suitable chips around these days which make this even
> easier. One of our local magazines published a video distribution amp
> design
> last year using a single chip amplifier that would be ideal. It has a high
> broadband gain and is designed to work into a 75 ohm load. When you think
> about it, there are a lot of similarities between the requirements for
> video
> distribution amps and HF multicouplers. 
> 
> Morris VK3DOC
> 
> 
> 
> --__--__--
> 
> Message: 2
> Subject: SV: [Premium-Rx] Antenna Couplers
> Date: Mon, 11 Nov 2002 11:29:47 +0100
> From: <Karl-Arne.A.Markstrom at telia.se>
> To: <premium-rx at ml.skirrow.org>
> 
> Hello all,
> 
> A small word of advice, learned the hard way, is to check the even order =
> intermodulation
> behaviour of any candidate for a wide-band amplifier intended for =
> antenna multicoupler service.
> 
> Single-ended wide-band amplifiers usually have inferior even-order IM =
> than most premium receivers,=20
> even if they show very good odd-order performance, and to stay out of =
> hard-to-locate IM trouble
> especially when using large wide-band antennas it is advisable to use =
> some form of balanced circuit.
> 
> The best performers in my experience have been the balanced Norton =
> designs used in the Anzac AM-109,
> the balanced preamps described by N6NWP in QST, and the DC coupled and =
> heavy negative feedback
> "totem-pole" design used in the Rodhe & Schwarz NV-14.
> 
> Would be interesting to hear of anybody's experience using the =
> Mini-Circuits HELA high-dynamic range
> balanced monolithic preamp as the wide-band amplifier in a HF =
> multicoupler.
> 
> 73/
> 
> Karl-Arne Markstrom
> SM0AOM
> 
> Senior Radio Engineer
> Maritime Networks
> Telia Mobile AB Nacka Strand Sweden
> 
> Phone +46-8-6017171=20
> Mobile +46-706-636575
> Fax +46-8-6017959=20
> 
> 
> 
> -----Ursprungligt meddelande-----
> Fr=E5n: WF2U [mailto:wf2u at starband.net]
> Skickat: den 10 november 2002 20:50
> Till: premium-rx at ml.skirrow.org
> =C4mne: RE: [Premium-Rx] Antenna Couplers
> 
> 
> About 10 years ago when I still making a living as an EE, I designed and
> built an 8 port hybrid splitter array, with a preamp which made up for =
> the
> overall insertion loss, giving a net gain of around 2 db. The preamp I =
> used
> was one of the wide-band Motorola "brick" amplifier modules, (I think =
> 100
> KHz to 100 MHz,  the model number eludes me now, I have to look at my
> coupler) with 1 W out  at -1dB. I also put  a 1.6 MHz high-pass filter =
> at
> the input of the  preamp as to minimize possible intermod from the =
> broadcast
> band. I forgot what the noise figure was, but it wasn't anything to be
> significant on HF.
> The coupler works very well,  I built it in a  4" x 6" cast aluminum =
> box,
> with an external 24 VDC supply built into a similar box.
> 
> 73, Meir WF2U
> Landrum, SC
> 
>  -----Original Message-----
> From: 	premium-rx-admin at ml.skirrow.org
> [mailto:premium-rx-admin at ml.skirrow.org]  On Behalf Of James C. Garland
> Sent:	Sunday, November 10, 2002 1:25 PM
> To:	premium-rx at ml.skirrow.org
> Subject:	Re: [Premium-Rx] Antenna Couplers
> 
> 
> Does anyone have a circuit diagram of an active multicoupler? I'd like =
> try
> and homebrew one, and don't want to reinvent the wheel.
> Thanks,
> Jim Garland W8ZR
> 
> 
> _______________________________________________
> 
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> 
> --__--__--
> 
> Message: 3
> From: "Carcia, Frank A.           HS" <francis.carcia at hs.utc.com>
> To: "'Al Klase'" <skywaves at bw.webex.net>,
>    "James C. Garland"
> 	 <4cx250b at muohio.edu>
> Cc: premium-rx at ml.skirrow.org
> Subject: RE: [Premium-Rx] Antenna Couplers
> Date: Mon, 11 Nov 2002 07:51:14 -0500
> 
> hi All,
> That Rhode amplifier works very well.
> 					fc
> 
> -----Original Message-----
> From: Al Klase [mailto:skywaves at bw.webex.net]
> Sent: Sunday, November 10, 2002 2:34 PM
> To: James C. Garland
> Cc: premium-rx at ml.skirrow.org
> Subject: Re: [Premium-Rx] Antenna Couplers
> 
> 
> Hi Jim,
> 
> I I've owned and used a number of military couplers.  The
> whole house is currently fed from a CU-1280 via 75-ohm TV
> coax and fittings.  I'd don't have documentation for either
> of the units I currently have, but I think I can provide
> some useful info.  
> 
> For general SWL use, you can get away with passive splitters
> for maybe two or four radios.  Keep in mind that you'll have
> a 3db loss each time you do a 1:2 split only if you use a
> proper hybrid.  The hybrid also provides about 30dB
> isolation between outputs that keep the receivers from
> bothering each other.  There's a good design detailed on my
> website in the "SWL Antennas" systems section. To split four
> ways you need three 1:2 couplers.
> 
> The antenna multicouplers are generally set up one of two
> ways: (1) An amplifier, with enough gain to make up the
> subsequent losses feeds an array of splitters. Maybe 1:8 or
> even 1:16. (2) A low gain amp feeds a bus that drives an
> array of emitter followers that drive the individual
> outputs.
> 
> You have to keep in mind that the amplifier has to tolerate
> EVERYTHING that come down from the antenna.  This typically
> means a power amp with P1db in the 1-Watt+ range.  If you're
> devoid of strong local signals you may be able to cheat on
> the amp.
> 
> There's an Ulrich Rhode article in October 17 "Ham radio"
> that should do the job nicely.  It's two 2N5109's in
> push-pull with inductive feedback to preserve frequency
> response, linearity, and noise figure.  You could probably
> do this circuit with the same Amidon ferrite cores I specify
> for the splitters.
> 
> Regards,
> Al
> 
> "James C. Garland" wrote:
> > 
> > Does anyone have a circuit diagram of an active multicoupler? I'd like
> try
> > and homebrew one, and don't want to reinvent the wheel.
> > Thanks,
> > Jim Garland W8ZR
> > 
> > _______________________________________________
> > 
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> 
> -- 
> Al Klase - N3FRQ
> skywaves at bw.webex.net
> Flemington, NJ 08822
> Web Page:  http://www.webex.net/~skywaves/home.htm
> 
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> 
> --__--__--
> 
> Message: 4
> From: Aidehua at aol.com
> Date: Mon, 11 Nov 2002 12:40:43 EST
> Subject: Re: [Premium-Rx] Antenna Couplers
> To: francis.carcia at hs.utc.com
> CC: skywaves at bw.webex.net, 4cx250b at muohio.edu, premium-rx at ml.skirrow.org
> 
> 
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> 
> I have the Harris RF-654 and they work extremely well.  I got them new.
> The 
> range is 2-40 kHz and can be adapted to work down to 200 kHz by changing
> the 
> jumper...It will handle up to eight receivers and has a preamplifier
> built-in 
> to compensate for any losses.  Low noise, too!
> 
> 73,
> Ed
> 
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> 
> <HTML><FONT FACE=arial,helvetica><FONT  SIZE=2 FAMILY="SANSSERIF"
> FACE="Arial" LANG="0">I have the Harris RF-654 and they work extremely
> well.&nbsp; I got them new.&nbsp; The range is 2-40 kHz and can be adapted
> to work down to 200 kHz by changing the jumper...It will handle up to
> eight receivers and has a preamplifier built-in to compensate for any
> losses.&nbsp; Low noise, too!<BR>
> <BR>
> 73,<BR>
> Ed</FONT></HTML>
> 
> --part1_de.3022e7fc.2b01459b_boundary--
> 
> 
> 
> --__--__--
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