Re: [amsat-bb] Splitter for receiving system?
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 [email protected] To: AmsatBB [email protected] Subject: [amsat-bb] AMSAT-UK Colloquium 2015 ? Call For Speakers Message-ID: CAHOBG6XOyMpEuY2wedoZ-6znywEYp5u504jvpOkMej3afQx91w@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 [email protected] To: "Mark L. Hammond" [email protected] Cc: Amsat - BBs [email protected] Subject: Re: [amsat-bb] Splitter for receiving system? Message-ID: CAKXf1rF+WHKaFvf_e+J5PUDtq9S4bafk4wnc7mnKexwRxCLm7A@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 [email protected] 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 [email protected]. 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 [email protected] To: AMSAT BB [email protected] Subject: [amsat-bb] TYT TH-9000 on satellites Message-ID: CAHZ3kP9dob-=0Bk=gGUrC3-pVD0c4JDbL84JYZPK2Jq=ybj4RA@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" [email protected] To: Howie DeFelice [email protected] Cc: Amsat - BBs [email protected] Subject: Re: [amsat-bb] Splitter for receiving system? Message-ID: CAPRXzyqtTSBwJ6nK=0zWGtq857dNVuDvgik7Jb0TyYf9-4Tuiw@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 [email protected] 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: [email protected] To: [email protected] 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 [email protected]. 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 [email protected] To: AMSAT-BB [email protected] Subject: [amsat-bb] tracking software and Doppler interface Message-ID: [email protected] 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
[email protected] [email protected]
Message: 8 Date: Fri, 6 Feb 2015 21:37:04 -0500 From: Jacob Tennant [email protected] To: AMSAT-BB [email protected] Subject: [amsat-bb] The future of AMSAT launches??? Message-ID: CAMM2CtVRgdYqAt+uY7-7AWnMnjfWHdADJuGEuyM8VfQH8o5zhQ@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_Classi...
Jacob Tennant WF8S
Message: 9 Date: Fri, 6 Feb 2015 18:56:12 -0800 From: Bryce Salmi [email protected] To: Jacob Tennant [email protected] Cc: AMSAT-BB [email protected] Subject: Re: [amsat-bb] The future of AMSAT launches??? Message-ID: CAN5j0srRd2jHseAv7SNKch5=6-0XDA7TK8sb17DOXmsJ+EA=Rw@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 [email protected] 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_Classi...
Jacob Tennant WF8S _______________________________________________ Sent via [email protected] 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 [email protected] To: "[email protected]" [email protected] Cc: AMSAT-BB [email protected] Subject: Re: [amsat-bb] The future of AMSAT launches??? Message-ID: CA+7Uq1h=bCCLVoecnKJD+4cXxZ7wFwSUEN-OZV1OP8=cdC46Yg@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 [email protected] 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 <[email protected] 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_Classi...
Jacob Tennant WF8S _______________________________________________ Sent via [email protected] 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 [email protected] 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 [email protected] To: Jacob Tennant [email protected] Cc: AMSAT-BB [email protected] Subject: Re: [amsat-bb] The future of AMSAT launches??? Message-ID: CAN5j0sqm71Ro4Qc46s9Fqur=kRVc6gpOt6VeXoXkuSqNmTLrsQ@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 [email protected] 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_Classi...
Jacob Tennant WF8S _______________________________________________ Sent via [email protected]. 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 [email protected] To: [email protected] Subject: Re: [amsat-bb] The future of AMSAT launches??? Message-ID: [email protected] 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 [email protected] To: Gus [email protected] Cc: [email protected] Subject: Re: [amsat-bb] The future of AMSAT launches??? Message-ID: CAP7QzkPG-JTGd=cfG-xdu3CTZbLX5O=DTbfQGWLum_foEDkscA@mail.gmail.com Content-Type: text/plain; charset=UTF-8
On 2/7/15, Gus [email protected] 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 [email protected] To: Amsat - BBs [email protected] Subject: [amsat-bb] FUNCube Warehouse Outage Message-ID: [email protected] 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 [email protected]. 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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Mark L. Hammond