[amsat-bb] Splitter for receiving system?
Mark L. Hammond
marklhammond at gmail.com
Sat Feb 7 14:44:55 UTC 2015
Thanks to all the great replies and suggestions on this splitter thing. I ordered a pair of these Mini Circuit units (surplus, stateside) to have in the shack, and will try out when they come next week:
http://www.ebay.com/itm/270725394050
For my application, should work fine. Just has to be better than a TV splitter, if for no other reason than 75 ohms vs 50 ohms, SMA can be used here with fewer adapters, etc. :)
Mark N8MH
>Hello All,
>
>I am really wishing for a "splitter" for my receiving system, good for both
>2M and 70cm (so say, 144-450MHz or so.)
>
>Any suggestions? I really don't to lose 3dB in the process, but fear the
>only way to avoid that is some powered/amplified system. I recall such a
>device, but cannot for the life of me think where or the possible source.
>I do not need to xmit through it; receive only. Also, I do not need to
>pass 12V to power preamps, etc. So, just a low loss splitter good for 2M
>and 70cm. SMA, BNC, N connectors--any will work in my shack.
>
>Do folks refer to these as splitters? Combiners? Power splitters? I know
>about Mini Circuits--that's a sensory overload of stuff to pick through :)
>
>Any pointers to sources or such devices will be welcomed!
>
>
>
>Thanks---
>
>--
>Mark L. Hammond [N8MH]
>
>
>------------------------------
>
>Message: 3
>Date: Fri, 6 Feb 2015 14:05:20 +0000
>From: David Johnson <dave at g4dpz.me.uk>
>To: AmsatBB <amsat-bb at amsat.org>
>Subject: [amsat-bb] AMSAT-UK Colloquium 2015 ? Call For Speakers
>Message-ID:
> <CAHOBG6XOyMpEuY2wedoZ-6znywEYp5u504jvpOkMej3afQx91w at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>This is the first call for speakers for the AMSAT-UK Colloquium 2015
>which will be held from Saturday, July 25 to Sunday, July 26 2015 at
>the Holiday Inn, Guildford, GU2 7XZ, United Kingdom.
>
>http://amsat-uk.org/colloquium/colloquium-2015/
>
>AMSAT-UK invites speakers, to cover topics about micro-satellites,
>CubeSats, Nanosats, space and associated activities, for this event.
>
>They are also invited to submit papers for subsequent publishing on
>the AMSAT-UK web site. We normally prefer authors to present talks
>themselves rather than having someone else give them in the authors?
>absence. We also welcome ?unpresented? papers for the web site.
>
>Submissions should be sent *ONLY* to G4DPZ, via the following routes:
>e-mail: dave at g4dpz dot me dot uk
>Postal address at http://www.qrz.com/db/G4DPZ
>
>AMSAT-UK also invite anyone with requests for Program Topics to submit
>them as soon as possible to G4DPZ. Invitations for any papers on
>specific subjects will be included in the future call. Likewise if
>anyone knows of a good speaker, please send contact and other
>information to G4DPZ.
>
>73
>
>Dave, G4DPZ
>
>
>------------------------------
>
>Message: 4
>Date: Fri, 6 Feb 2015 16:27:31 +0100
>From: Wouter Weggelaar <wouterweg at gmail.com>
>To: "Mark L. Hammond" <marklhammond at gmail.com>
>Cc: Amsat - BBs <amsat-bb at amsat.org>
>Subject: Re: [amsat-bb] Splitter for receiving system?
>Message-ID:
> <CAKXf1rF+WHKaFvf_e+J5PUDtq9S4bafk4wnc7mnKexwRxCLm7A at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>Hi Mark,
>
>As you already mentioned, the 3dB is just the split itself. atop of that,
>you will get some loss in the actual splitter.
>There is indeed no way around this 3dB, because thats just what happens
>when you split the signal into two equal parts. you can minimise the loss
>though.
>If you have a pre-amplifier with sufficient gain, you may not actually have
>to worry too much about this, but without one, all the decibels add up to
>your noise figure!
>
>So do you have a pre-amplifier? You mentioned not having to pass 12V, but
>that does not mean you don't have one..;)
>If you have, dont worry about the power loss in the splitting process.
>
>I am using minicircuits ZFSC-2-1, but thats just a junkbox find without
>selection.
>
>
>Wouter PA3WEG
>
>On Fri, Feb 6, 2015 at 2:00 PM, Mark L. Hammond <marklhammond at gmail.com>
>wrote:
>
>> Hello All,
>>
>> I am really wishing for a "splitter" for my receiving system, good for both
>> 2M and 70cm (so say, 144-450MHz or so.)
>>
>> Any suggestions? I really don't to lose 3dB in the process, but fear the
>> only way to avoid that is some powered/amplified system. I recall such a
>> device, but cannot for the life of me think where or the possible source.
>> I do not need to xmit through it; receive only. Also, I do not need to
>> pass 12V to power preamps, etc. So, just a low loss splitter good for 2M
>> and 70cm. SMA, BNC, N connectors--any will work in my shack.
>>
>> Do folks refer to these as splitters? Combiners? Power splitters? I know
>> about Mini Circuits--that's a sensory overload of stuff to pick through :)
>>
>> Any pointers to sources or such devices will be welcomed!
>>
>>
>>
>> Thanks---
>>
>> --
>> Mark L. Hammond [N8MH]
>> _______________________________________________
>> Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
>> to all interested persons worldwide without requiring membership. Opinions
>> expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>
>
>------------------------------
>
>Message: 5
>Date: Fri, 6 Feb 2015 11:22:59 -0600
>From: John Geiger <af5cc at fidmail.com>
>To: AMSAT BB <amsat-bb at amsat.org>
>Subject: [amsat-bb] TYT TH-9000 on satellites
>Message-ID:
> <CAHZ3kP9dob-=0Bk=gGUrC3-pVD0c4JDbL84JYZPK2Jq=ybj4RA at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>Has anyone used one of the TYT TH-9000 UHF models on the satellites? I am
>currently using a Baofeng UV-3R Plus for the SO50 downlink, and think that
>the receive could be better on a different radio. The price is nice for
>the TYT for a brand new FM UHF rig.
>
>The Jetstream JTS-270M also looks tempting for a dualbander.
>
>73 John AF5CC
>
>
>------------------------------
>
>Message: 6
>Date: Fri, 6 Feb 2015 17:51:16 -0500
>From: "Mark L. Hammond" <marklhammond at gmail.com>
>To: Howie DeFelice <howied231 at hotmail.com>
>Cc: Amsat - BBs <amsat-bb at amsat.org>
>Subject: Re: [amsat-bb] Splitter for receiving system?
>Message-ID:
> <CAPRXzyqtTSBwJ6nK=0zWGtq857dNVuDvgik7Jb0TyYf9-4Tuiw at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>Thanks everybody for the great help. I didn't describe my setup or goals
>very well...but lots of ideas coming in.
>
>I have multiple SDRs in the shack now. I have a 2M array with low
>noise/high gain preamp and 70cm array with low noise/high gain preamp that
>I use for receive only (mast mount preamps, externally powered). So, my
>goal is any band with any SDR, no switching or cables. Even 2 SDRs, same
>band, same time...so here is what I envision:
>
>I have separate feedlines coming into the shack--one for 2M one for 70cm.
>Tie them together via a single diplexer. Then, the single diplexer output
>(carrying both 2M and 70cm) going into a splitter with multiple
>outputs--going to FCDPP, Airspy, whatever...with a single split, it's 3dB.
>
>The easy and cheapest solution had occurred to me---which is use a
>cable/satellite TV splitter (I know, 75 ohms). But a good idea from one of
>you was to get the "variable amplified" version from RadioShack or
>wherever. I was thinking something more "elegant" at 50 ohms might be
>worth while.
>
>I'll probably try to the TV splitter and see how it works and if the loss
>is OK. Shouldn't be bad, given the preamps.
>
>Anyhow, fun to chat about--thanks for all the private and public
>responses. Once I get a bit more time, I'll try to summarize some other
>suggests a little better.
>
>73!
>
>Mark N8MH
>
>
>
>
>
>On Fri, Feb 6, 2015 at 10:30 AM, Howie DeFelice <howied231 at hotmail.com>
>wrote:
>
>> Hi Mark, no matter what you use you will lose 3 db + the splitter
>> insertion loss. If you are putting the splitter after a LNA, then the added
>> loss is usually not important. However, if you are putting the splitter
>> directly between the antenna and your receiver the loss of the splitter
>> will add directly to the receiver noise figure, which in weak signal work
>> is the real difference between hearing and not hearing a signal.
>>
>> If you can afford the 3+ dB increase in system noise figure, a plain old
>> TV splitter is actually not bad. The outdoor variety are water tight,
>> F-connectors are pretty good at UHF (in some ways better than a BNC). If
>> it's RX only, RG-6 is low loss, inexpensive and the slight mis-match is not
>> that significant.
>>
>> If noise figure is important, a low gain, low noise figure amp before the
>> splitter (which can be turned around and used as a combiner) is a good idea.
>>
>> Mini-circuits are great components and have a great variety of quality
>> RF/IF components. The only problem is that their distribution network is
>> limited and unless you find a retail source that has what you want getting
>> parts can be a little difficult .... and you will start getting called by
>> the "area rep" wanting to know how many hundred you will be needing every
>> few months :) That said, they HAVE been accomodating when I needed
>> something that wasn't available through distribution.
>>
>> - Howie, AB2S
>>
>>
>> > Date: Fri, 6 Feb 2015 08:00:04 -0500
>> > From: marklhammond at gmail.com
>> > To: amsat-bb at amsat.org
>> > Subject: [amsat-bb] Splitter for receiving system?
>> >
>> > Hello All,
>> >
>> > I am really wishing for a "splitter" for my receiving system, good for
>> both
>> > 2M and 70cm (so say, 144-450MHz or so.)
>> >
>> > Any suggestions? I really don't to lose 3dB in the process, but fear the
>> > only way to avoid that is some powered/amplified system. I recall such a
>> > device, but cannot for the life of me think where or the possible source.
>> > I do not need to xmit through it; receive only. Also, I do not need to
>> > pass 12V to power preamps, etc. So, just a low loss splitter good for 2M
>> > and 70cm. SMA, BNC, N connectors--any will work in my shack.
>> >
>> > Do folks refer to these as splitters? Combiners? Power splitters? I know
>> > about Mini Circuits--that's a sensory overload of stuff to pick through
>> :)
>> >
>> > Any pointers to sources or such devices will be welcomed!
>> >
>> >
>> >
>> > Thanks---
>> >
>> > --
>> > Mark L. Hammond [N8MH]
>> > _______________________________________________
>> > Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
>> > to all interested persons worldwide without requiring membership.
>> Opinions expressed
>> > are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> > Not an AMSAT-NA member? Join now to support the amateur satellite
>> program!
>> > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>
>
>
>--
>Mark L. Hammond [N8MH]
>
>
>------------------------------
>
>Message: 7
>Date: Fri, 06 Feb 2015 16:59:30 -0700
>From: Jim White <jim at coloradosatellite.com>
>To: AMSAT-BB <amsat-bb at amsat.org>
>Subject: [amsat-bb] tracking software and Doppler interface
>Message-ID: <54D55562.60001 at coloradosatellite.com>
>Content-Type: text/plain; charset=utf-8; format=flowed
>
>Before I start buying stuff I want to be sure the following setup will work.
>
>SatPC.
>USB interface to an LVB tracker to a G-5400B (DIN connector).
>USB CI-5 interface cable (EBay) to IC910 for Doppler and freq control.
>
>(I assume) USB - serial adapter to M2 RC2800 rotor controller
>
>Can anyone advise if that config will work? Anything else I need for
>rotor (2 different ones) and radio (IC-910) control?
>
>Can I buy an LVB tracker assembled and tested? All I see on the AMSAT
>web site is extras for it.
>
>Thanks,
>Jim
>
>jim at coloradsosatellite.com
>wd0e at amsat.org
>
>
>------------------------------
>
>Message: 8
>Date: Fri, 6 Feb 2015 21:37:04 -0500
>From: Jacob Tennant <jakewf8s at gmail.com>
>To: AMSAT-BB <amsat-bb at amsat.org>
>Subject: [amsat-bb] The future of AMSAT launches???
>Message-ID:
> <CAMM2CtVRgdYqAt+uY7-7AWnMnjfWHdADJuGEuyM8VfQH8o5zhQ at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>This seems so smart that I don't know why they haven't done this already.
>
>http://www.engadget.com/2015/02/06/darpa-alasa-video/?utm_source=Feed_Classic_Full&utm_medium=feed&utm_campaign=Engadget&?ncid=rss_full
>
>Jacob Tennant WF8S
>
>
>------------------------------
>
>Message: 9
>Date: Fri, 6 Feb 2015 18:56:12 -0800
>From: Bryce Salmi <bstguitarist at gmail.com>
>To: Jacob Tennant <jakewf8s at gmail.com>
>Cc: AMSAT-BB <amsat-bb at amsat.org>
>Subject: Re: [amsat-bb] The future of AMSAT launches???
>Message-ID:
> <CAN5j0srRd2jHseAv7SNKch5=6-0XDA7TK8sb17DOXmsJ+EA=Rw at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>This has existed for a long time. There's not much new.
>
>The rocket equation tells you that you need lots of fuel to send mass to
>orbit. That is referred to as delta V, change in velocity. LEO is about
>17,500 mph, this jet gets to maybe 1,000 mph?
>
>Most rockets are not big because they can be, they are big because they
>have to be.
>
>This project isn't actually getting to orbit yet. Is it actually 1 million
>in cost to get there or is that before profit? Then you're talking more
>like 3-4 million at minimum.
>
>Bryce
>
>On Friday, February 6, 2015, Jacob Tennant <jakewf8s at gmail.com> wrote:
>
>> This seems so smart that I don't know why they haven't done this already.
>>
>>
>> http://www.engadget.com/2015/02/06/darpa-alasa-video/?utm_source=Feed_Classic_Full&utm_medium=feed&utm_campaign=Engadget&?ncid=rss_full
>>
>> Jacob Tennant WF8S
>> _______________________________________________
>> Sent via AMSAT-BB at amsat.org <javascript:;>. AMSAT-NA makes this open
>> forum available
>> to all interested persons worldwide without requiring membership. Opinions
>> expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>
>
>------------------------------
>
>Message: 10
>Date: Fri, 6 Feb 2015 19:02:37 -0800
>From: Brenton Salmi <kb1lqd at gmail.com>
>To: "bstguitarist at gmail.com" <bstguitarist at gmail.com>
>Cc: AMSAT-BB <amsat-bb at amsat.org>
>Subject: Re: [amsat-bb] The future of AMSAT launches???
>Message-ID:
> <CA+7Uq1h=bCCLVoecnKJD+4cXxZ7wFwSUEN-OZV1OP8=cdC46Yg at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>For $1 million that's a small rocket. The only benefit to airplane launched
>rocket is any orbit anytime, very nice in the spy world too :)
>
>Also, likely not much of a secondary payload so you're likely buys all of
>the rocket unlike jumping on as cheap ballast to a big rocket.
>
>Just give the free Kerbal space program game a spin and you'll realize how
>easy it is to get 400km high but very very hard and lots of fuel to get to
>orbit... Which is the point of satellites!
>
>Interesting article though!
>
>On Friday, February 6, 2015, Bryce Salmi <bstguitarist at gmail.com> wrote:
>
>> This has existed for a long time. There's not much new.
>>
>> The rocket equation tells you that you need lots of fuel to send mass to
>> orbit. That is referred to as delta V, change in velocity. LEO is about
>> 17,500 mph, this jet gets to maybe 1,000 mph?
>>
>> Most rockets are not big because they can be, they are big because they
>> have to be.
>>
>> This project isn't actually getting to orbit yet. Is it actually 1 million
>> in cost to get there or is that before profit? Then you're talking more
>> like 3-4 million at minimum.
>>
>> Bryce
>>
>> On Friday, February 6, 2015, Jacob Tennant <jakewf8s at gmail.com
>> <javascript:;>> wrote:
>>
>> > This seems so smart that I don't know why they haven't done this already.
>> >
>> >
>> >
>> http://www.engadget.com/2015/02/06/darpa-alasa-video/?utm_source=Feed_Classic_Full&utm_medium=feed&utm_campaign=Engadget&?ncid=rss_full
>> >
>> > Jacob Tennant WF8S
>> > _______________________________________________
>> > Sent via AMSAT-BB at amsat.org <javascript:;> <javascript:;>. AMSAT-NA
>> makes this open
>> > forum available
>> > to all interested persons worldwide without requiring membership.
>> Opinions
>> > expressed
>> > are solely those of the author, and do not reflect the official views of
>> > AMSAT-NA.
>> > Not an AMSAT-NA member? Join now to support the amateur satellite
>> program!
>> > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>> >
>> _______________________________________________
>> Sent via AMSAT-BB at amsat.org <javascript:;>. AMSAT-NA makes this open
>> forum available
>> to all interested persons worldwide without requiring membership. Opinions
>> expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>
>
>------------------------------
>
>Message: 11
>Date: Fri, 6 Feb 2015 19:34:28 -0800
>From: Bryce Salmi <bstguitarist at gmail.com>
>To: Jacob Tennant <jakewf8s at gmail.com>
>Cc: AMSAT-BB <amsat-bb at amsat.org>
>Subject: Re: [amsat-bb] The future of AMSAT launches???
>Message-ID:
> <CAN5j0sqm71Ro4Qc46s9Fqur=kRVc6gpOt6VeXoXkuSqNmTLrsQ at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>More info:
>
>This ALASA concept/project:
>https://en.wikipedia.org/wiki/Airborne_Launch_Assist_Space_Access
>
>Pegasus (An already flying air launch orbital rocket) which cost $11
>million per launch.. in 1994: https://en.wikipedia.org/wiki/Pegasus_(rocket)
>
>Video of a launch! https://www.youtube.com/watch?v=lFUPkYre06E
>
>Bryce
>KB1LQC
>
>On Fri, Feb 6, 2015 at 6:37 PM, Jacob Tennant <jakewf8s at gmail.com> wrote:
>
>> This seems so smart that I don't know why they haven't done this already.
>>
>>
>> http://www.engadget.com/2015/02/06/darpa-alasa-video/?utm_source=Feed_Classic_Full&utm_medium=feed&utm_campaign=Engadget&?ncid=rss_full
>>
>> Jacob Tennant WF8S
>> _______________________________________________
>> Sent via AMSAT-BB at amsat.org. AMSAT-NA makes this open forum available
>> to all interested persons worldwide without requiring membership. Opinions
>> expressed
>> are solely those of the author, and do not reflect the official views of
>> AMSAT-NA.
>> Not an AMSAT-NA member? Join now to support the amateur satellite program!
>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
>>
>
>
>------------------------------
>
>Message: 12
>Date: Sat, 07 Feb 2015 00:05:52 -0400
>From: Gus <gus at 8p6sm.net>
>To: amsat-bb at amsat.org
>Subject: Re: [amsat-bb] The future of AMSAT launches???
>Message-ID: <54D58F20.1010406 at 8p6sm.net>
>Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
>On 02/06/2015 10:56 PM, Bryce Salmi wrote:
>> This has existed for a long time. There's not much new.
>>
>>
>The idea of using an F-15 as a launch platform has been around for
>decades. The Starwars program planned to use this technique to shoot
>down enemy satellites in wartime. And that was back when Reagan was in
>the Whitehouse.
>
>--
>Gus 8P6SM
>The Easternmost Isle
>
>
>
>------------------------------
>
>Message: 13
>Date: Sat, 7 Feb 2015 05:02:46 +0000
>From: B J <va6bmj at gmail.com>
>To: Gus <gus at 8p6sm.net>
>Cc: amsat-bb at amsat.org
>Subject: Re: [amsat-bb] The future of AMSAT launches???
>Message-ID:
> <CAP7QzkPG-JTGd=cfG-xdu3CTZbLX5O=DTbfQGWLum_foEDkscA at mail.gmail.com>
>Content-Type: text/plain; charset=UTF-8
>
>On 2/7/15, Gus <gus at 8p6sm.net> wrote:
>> On 02/06/2015 10:56 PM, Bryce Salmi wrote:
>>> This has existed for a long time. There's not much new.
>>>
>>>
>> The idea of using an F-15 as a launch platform has been around for
>> decades. The Starwars program planned to use this technique to shoot
>> down enemy satellites in wartime. And that was back when Reagan was in
>> the Whitehouse.
>
><snip>
>
>The feasibility of this was demonstrated in a test conducted nearly 30
>years ago. An F-15 launched a small rocket and it destroyed a defunct
>satellite.
>
>73s
>
>Bernhard VA6BMJ @ DO33FL
>
>
>------------------------------
>
>Message: 14
>Date: Sat, 07 Feb 2015 09:10:08 +0000
>From: David A B Johnson <dave at g4dpz.me.uk>
>To: Amsat - BBs <amsat-bb at amsat.org>
>Subject: [amsat-bb] FUNCube Warehouse Outage
>Message-ID: <54D5D670.40208 at g4dpz.me.uk>
>Content-Type: text/plain; charset=utf-8; format=flowed
>
>Hi,
>
>The hosted server was restarted at 01:50 UTC on Saturday morning by the
>hosting company.
>
>Whilst the server itself came up cleanly, the warehouse and data web
>services did not.
>
>We therefore lost about 7 hours of data, 0.0006% of all data :-)
>
>Will fix the startup process so that it doesn't happne again.
>
>73
>
>- Dave
>
>
>------------------------------
>
>_______________________________________________
>Sent via amsat-bb at amsat.org.
>AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed
>are solely those of the author, and do not reflect the official views of AMSAT-NA.
>Not an AMSAT member? Join now to support the amateur satellite program!
>http://amsat.org/mailman/listinfo/amsat-bb
>
>End of AMSAT-BB Digest, Vol 10, Issue 46
>****************************************
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