[amsat-bb] Re: TARDIS in Space.
You could donate to the FOX-2 project. 73, John KD6OZH - Original Message - $33,000 isn't a lot of money I mean for a community project ... no I don't have $33K to kick in ... but maybe I have $100 for LEO cube sat with a linear transponder in an orbit that lasts more than 3 weeks ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: 2m--> 10.7Mhz downconverter
For a demonstration, the easiest route would be to modify a 2-meter receiving downconverter from Down East Microwave or another supplier. Change the crystal oscillator frequency and retune the IF output to 10.7 MHz. If you have a choice of IF frequencies use 21.4 MHz as this would be closer to the usual 28 MHz output. 73, John KD6OZH - Original Message - From: "Andy Brian" To: "AMSAT-BB" Sent: Friday, October 04, 2013 04:45 UTC Subject: [amsat-bb] 2m--> 10.7Mhz downconverter Hi, I need help to find any good design for the 2m to 10.7MHz downconverter which I'll try to use for presentation linear transverter. Please if you have any or point me to any good books where to find? Thanks for all answers, BR Andy ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Phase 3
AMSAT-DL was the lead for phase 3 because they were able to get almost-free launches from ESA. However, ESA terminated that policy 10 years ago and AMSAT-DL has been trying to get government funding through their Mars program. That was rejected a year or two ago. Private launch companies are asking for $8,000,000..The world-wide fund raising by AMSAT-DL, AMSAT-UK, AMSAT-NA, AMSAT-Japan, ARRL and RSGB for each of the phase 3 launches acheived less than 10% of what is now required for a launch. In the past, a launch opportunity was identified by ESA and then a satellite was built by AMSAT. P3E did the reverse -- building a satellite and hoping for a launch. I brought up AMSAT-DL because someone was complaining that AMSAT-NA was leading them on about HEO possibilities. They should review videos of the AMSAT-DL presentations at the annual AMSAT-UK meetings. AMSAT-NA has been much more realistic. 73, John KD6OZH - Original Message - From: "Rob" To: Sent: Friday, September 20, 2013 12:34 UTC Subject: [amsat-bb] Phase 3 Wait wasn't AMSAT-DL always the lead when it came to Phase-3 satellites ??? Also, AMSAT-DL has a platform already constructed awaiting launch opportunity. http://amsat-uk.org/2013/02/25/the-next-amsat-phase-3-satellite/ Issues with ITAR aside, why can't we just support our international partners ... somehow ... ??? Getting an amateur radio satellite into orbit costs real green dollars (Euros, GBP, whatever) we would do better pooling resources for the good of all. There are all kinds of players in the launch market these days US, ESA, Russia, China, Japan, India and a lot of up and coming private launch vendors call me naive but I think conditions are BETTER now (ITAR aside) than they were in the days of AO-10 Why can't we focus on the possibilities de KA2PBT On Fri, Sep 20, 2013 at 2:30 AM, John Stephensen wrote: AMSAT-NA abandoned the Eagle project years ago. Only AMSAT-DL has an "active" HEO project. with P3E. 73, John KD6OZH ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Phase 3
The problem is that the government is no longer paying for those expenses as they did in the past. The $8,000,000 is the incremental cost not the cost of the entire launch. 73, John KD6OZH - Original Message - From: "Rob" To: Sent: Friday, September 20, 2013 15:54 UTC Subject: [amsat-bb] Re: Phase 3 I don't think we'll ever be in a position to "buy" a launch the most we will ever be able to do is hope to piggy-back with a paying customer and possibly contribute to "expenses." Maybe having a payload "on the shelf ready" isn't such a bad plan if a "short window of opportunity" were to open up ... and we had nothing ready that would be an opportunity lost. Maybe we should have various payloads sitting on the shelf (cube, micro, mini, P3) just in case. Piggy-back rides is how Amateur Radio Satellites got their start it's the only way to continue. --> Rob, KA2PBT On Fri, Sep 20, 2013 at 3:27 PM, John Stephensen wrote: AMSAT-DL was the lead for phase 3 because they were able to get almost-free launches from ESA. However, ESA terminated that policy 10 years ago and AMSAT-DL has been trying to get government funding through their Mars program. That was rejected a year or two ago. Private launch companies are asking for $8,000,000..The world-wide fund raising by AMSAT-DL, AMSAT-UK, AMSAT-NA, AMSAT-Japan, ARRL and RSGB for each of the phase 3 launches acheived less than 10% of what is now required for a launch. In the past, a launch opportunity was identified by ESA and then a satellite was built by AMSAT. P3E did the reverse -- building a satellite and hoping for a launch. I brought up AMSAT-DL because someone was complaining that AMSAT-NA was leading them on about HEO possibilities. They should review videos of the AMSAT-DL presentations at the annual AMSAT-UK meetings. AMSAT-NA has been much more realistic. 73, John KD6OZH ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: Phase 3
The problem is that the government is no longer paying for those expenses as they did in the past. 73, John KD6OZH - Original Message - From: "Rob" To: Sent: Friday, September 20, 2013 15:54 UTC Subject: [amsat-bb] Re: Phase 3 I don't think we'll ever be in a position to "buy" a launch the most we will ever be able to do is hope to piggy-back with a paying customer and possibly contribute to "expenses." Maybe having a payload "on the shelf ready" isn't such a bad plan if a "short window of opportunity" were to open up ... and we had nothing ready that would be an opportunity lost. Maybe we should have various payloads sitting on the shelf (cube, micro, mini, P3) just in case. Piggy-back rides is how Amateur Radio Satellites got their start it's the only way to continue. --> Rob, KA2PBT On Fri, Sep 20, 2013 at 3:27 PM, John Stephensen wrote: AMSAT-DL was the lead for phase 3 because they were able to get almost-free launches from ESA. However, ESA terminated that policy 10 years ago and AMSAT-DL has been trying to get government funding through their Mars program. That was rejected a year or two ago. Private launch companies are asking for $8,000,000..The world-wide fund raising by AMSAT-DL, AMSAT-UK, AMSAT-NA, AMSAT-Japan, ARRL and RSGB for each of the phase 3 launches acheived less than 10% of what is now required for a launch. In the past, a launch opportunity was identified by ESA and then a satellite was built by AMSAT. P3E did the reverse -- building a satellite and hoping for a launch. I brought up AMSAT-DL because someone was complaining that AMSAT-NA was leading them on about HEO possibilities. They should review videos of the AMSAT-DL presentations at the annual AMSAT-UK meetings. AMSAT-NA has been much more realistic. 73, John KD6OZH ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: so long
AMSAT-NA abandoned the Eagle project years ago. Only AMSAT-DL has an "active" HEO project. with P3E. 73, John KD6OZH - Original Message - From: "Michael" To: Sent: Thursday, September 19, 2013 21:06 UTC Subject: [amsat-bb] Re: so long I said this a couple of weeks back but since reading all the responses in this thread, I think I'll say it again. I'm almost fifty one years old. I highly doubt that I will ever see an HEO bird launched in my remaining lifetime. The economic realities of this day and time make the possibility of a launch extremely remote and I don't see that changing in the near future. I can't understand why AMSAT continues to string people along with promises of "maybe someday if you donate". Why can't they just be upfront about it and tell people, " Hey it aint going to happen". There is absolutely nothing wrong with the new direction AMSAT has taken in pursuing cubesat technology and launches, I applaud them for it but the continued lip service to the " we want an HEO crowd" gets old. I for one am not that gullible. Quit telling people what they want to hear and tell them the truth. 73, Michael, W4HIJ On 9/17/2013 7:02 PM, i8cvs wrote: - Original Message - From: "John Becker" To: Sent: Tuesday, September 17, 2013 8:58 PM Subject: [amsat-bb] so long I have decided to leave the list till something changes with this FM only satellite attitude only changes. That was the reason for me as well as other joining AMSAT in the first place. Please inform me if anything such as a replacement for AO 40 happens. John Hi John,W0JAB I was AMSAT member numbar 798 since OSCAR-6 but I decided to live my membership after AO40 died because AMSAT changed his policy with only FM satellites. I remember that OSCAR-10,OSCAR13 and AO40 where called "the satellites for all" and I invested a lot of money for equipments and antennas dedicated for HEO satellites for nothing in the near future. In my opinion the satellite operation is not only an activity to collect grids but it is mostly experimentation in the VHF/UHF/SHF and particularly into microwave as it was with AO40 Mode-S/K and it was very nice until lasted. As soon AMSAT-NA will work or cooperate with AMSAT-DL to built a new HEO satellite I will call Martha and I will pay all my old duties to cover my previous not covered years of membership. By the way I am not against AMSAT-NA because I understand the ITAR and during the last 10 years I have cooperate to write many technical articles for the AMSAT Journal without any money reward. If Martha says that the actual AMSAT members are in the order of 3,000. and if Les Rayburn, N1LF claim to be member of AMSAT #38965 it means that in the last 10 years many members abandoned AMSAT because of no future with no HEO satellites and only the FM LEO cubesat for no two ways communications between continents was not a satisfactory task. Many years ago early in 1972 I joined AMSAT because they promised us to communicate worlwide much better than using the HF but things changed and our antennas are becaming rusty over the roof for very small or for nothingSorry ! 73" de i8CVS Domenico ___ ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: AO-40 Replacement
New equipment wouldn't be needed. The concept is to use the PCs that amateurs already have to fit more QSOs into the downlink. Uplink frequency coordination isn't any harder than on AO10, 13 or 40. 73, John KD6OZH - Original Message - From: "Virgil Bierschwale" To: "'John Stephensen'" ; "'Clint Bradford'" ; Sent: Thursday, September 05, 2013 03:13 UTC Subject: RE: [amsat-bb] Re: AO-40 Replacement You also could develop a whole new line of amateur radio equipment. By that, I mean that ham's could use existing transceivers, and for satellites that were equipped, they could buy this box that would allow them to transmit on channel ?? of frequency ?? and the same on receive. Of course, that might present a co-ordination nightmare... Virgil N5IVV -Original Message- From: John Stephensen [mailto:kd6...@comcast.net] Sent: Wednesday, September 04, 2013 9:25 PM To: Virgil Bierschwale; 'Clint Bradford'; amsat-bb@amsat.org Subject: Re: [amsat-bb] Re: AO-40 Replacement The satellite could collect the individual uplink signals and package them in one downlink. One TDM downlink would use much less power than FDM downlinks and would fit in the bandwidth of existing amateur receivers. Once you have DSP in the satellite, there are a lot of possibilities. 73, John KD6OZH ----- Original Message - From: "Virgil Bierschwale" To: "'John Stephensen'" ; "'Clint Bradford'" ; Sent: Thursday, September 05, 2013 01:52 UTC Subject: RE: [amsat-bb] Re: AO-40 Replacement I've enjoyed reading this segment and I wasn't going to touch it, but this one makes me want to chip in my two cents. Granted, I'm not up to speed on what ya'll have done or what you haven't done. But we used to use a ucc1 in the navy to receive messages. http://www.virhistory.com/navy/rtty-mux-ucc1.htm It would allow us to receive something like 16 or 32 separate traffic channels on one frequency. Wouldn't it be possible to develop something like that in satellite communications? I ask because if you were to do it, you could substantially increase the amount of channels that you could process? Virgil N5IVV -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of John Stephensen Sent: Wednesday, September 04, 2013 8:31 PM To: Clint Bradford; amsat-bb@amsat.org Subject: [amsat-bb] Re: AO-40 Replacement If we want the most "bang for the buck", it would be something that supports the most QSOs per watt of solar power. Since most hams have computers, something that supports half a dozen PSK31 sessions would suffice. Given the new open-source voice codec you could also make something that supports multiple digital voice QSOs with less power than now required for analog FM or SSB. 73, John KD6OZH - Original Message - From: "Clint Bradford" To: ; Sent: Thursday, September 05, 2013 00:27 UTC Subject: [amsat-bb] Re: AO-40 Replacement ... launch opportunities are so rare that we ought to fly the most capable equipment we can on those rare occasions when we can get a launch ... Perhaps we should define, "most capable equipment." And we also need to define "bang for the buck." ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: A0 40 replacement (PSK31-Best of FM and Linear!)
The FM PA can be more efficient than the linear PA. If you constrain the FM deviation to be very narrow you can get 6 dB greater power efficiency for FM given a fixed peak envelope power ("HF Radio Systems and Circuits," page 59). 73, John KD6OZH - Original Message - From: "Robert Bruninga" To: Sent: Thursday, September 05, 2013 12:44 UTC Subject: [amsat-bb] A0 40 replacement (PSK31-Best of FM and Linear!) As long as AMSAT-NA needs to concentrate on... Cubesats... I would really like to see the pursuit of linear transponders... on them instead of single-channel FM repeaters. We can have the best of BOTH FM and Linear! But we used to use a ucc1 in the navy to receive messages. http://www.virhistory.com/navy/rtty-mux-ucc1.htm It would allow us to receive something like 16 or 32 separate traffic channels on one frequency. We have that now in PSK31. Up to 30 channels in a single audio channel. So the ideal AMSAT transponder is a linear receiver (on 28.120 MHz) and an FM downlink of that single channel on UHF. This has the advantage of 30 individual linear uplinks to share amongst everyone, and the advantage of FM downlink so that everyone gets the same waterfall without added Doppler. It's a win/win. And it is FULL duplex so that everyone can transmit simultaneously and everyone can receive everyone simultaneously. What more fun can that be!!! See the design: http://aprs.org/psk31uplink2.html And it all fits on a single 3.4" circuit board. Easy to fit in any Cubesat. Two such flight ready boards are ready by the Brno University in the CZECH Republic. Bob, WB4APR ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: AO-40 Replacement
The satellite could collect the individual uplink signals and package them in one downlink. One TDM downlink would use much less power than FDM downlinks and would fit in the bandwidth of existing amateur receivers. Once you have DSP in the satellite, there are a lot of possibilities. 73, John KD6OZH - Original Message - From: "Virgil Bierschwale" To: "'John Stephensen'" ; "'Clint Bradford'" ; Sent: Thursday, September 05, 2013 01:52 UTC Subject: RE: [amsat-bb] Re: AO-40 Replacement I've enjoyed reading this segment and I wasn't going to touch it, but this one makes me want to chip in my two cents. Granted, I'm not up to speed on what ya'll have done or what you haven't done. But we used to use a ucc1 in the navy to receive messages. http://www.virhistory.com/navy/rtty-mux-ucc1.htm It would allow us to receive something like 16 or 32 separate traffic channels on one frequency. Wouldn't it be possible to develop something like that in satellite communications? I ask because if you were to do it, you could substantially increase the amount of channels that you could process? Virgil N5IVV -Original Message- From: amsat-bb-boun...@amsat.org [mailto:amsat-bb-boun...@amsat.org] On Behalf Of John Stephensen Sent: Wednesday, September 04, 2013 8:31 PM To: Clint Bradford; amsat-bb@amsat.org Subject: [amsat-bb] Re: AO-40 Replacement If we want the most "bang for the buck", it would be something that supports the most QSOs per watt of solar power. Since most hams have computers, something that supports half a dozen PSK31 sessions would suffice. Given the new open-source voice codec you could also make something that supports multiple digital voice QSOs with less power than now required for analog FM or SSB. 73, John KD6OZH - Original Message - From: "Clint Bradford" To: ; Sent: Thursday, September 05, 2013 00:27 UTC Subject: [amsat-bb] Re: AO-40 Replacement ... launch opportunities are so rare that we ought to fly the most capable equipment we can on those rare occasions when we can get a launch ... Perhaps we should define, "most capable equipment." And we also need to define "bang for the buck." ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: AO-40 Replacement
If we want the most "bang for the buck", it would be something that supports the most QSOs per watt of solar power. Since most hams have computers, something that supports half a dozen PSK31 sessions would suffice. Given the new open-source voice codec you could also make something that supports multiple digital voice QSOs with less power than now required for analog FM or SSB. 73, John KD6OZH - Original Message - From: "Clint Bradford" To: ; Sent: Thursday, September 05, 2013 00:27 UTC Subject: [amsat-bb] Re: AO-40 Replacement ... launch opportunities are so rare that we ought to fly the most capable equipment we can on those rare occasions when we can get a launch ... Perhaps we should define, "most capable equipment." And we also need to define "bang for the buck." ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: A0 40 replacement
The AMSAT-DL presentation at the AMSAT-UK meeting was that their goverment decided not to fund their HEO project and they are still looking for a source of money. AMSAT-NA and AMSAT-UK are concentrating on LEO projects that they can pay for via members and alliances with universities and government agencies. 73, John KD6OZH - Original Message - From: "John Becker" To: Sent: Tuesday, September 03, 2013 19:32 UTC Subject: [amsat-bb] A0 40 replacement Anything new on a replacement. Have not see a thing myself. John ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: AMSAT needs volunteers ???
Currently, the only way that AMSAT-NA seems to be able to work with non-US citizens is via NASA which can more easily obtain the required approvals. 73, John KD6OZH - Original Message - From: "Jaime Robles" To: Sent: Friday, June 07, 2013 18:37 UTC Subject: [amsat-bb] Re: AMSAT needs volunteers ??? I answered last year to a call and I got an answer from AMSAT ... but it was negative due to the ITAR regulations and my Spanish nationality :-) Maybe if the US relax ITAR for hamradio satellites we (non-US hams) can help in future projects. :-) Just my 2 cents :-) Jaime, EA4TV El 07/06/2013 19:43, "John Stephensen" escribió: ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: AMSAT needs volunteers ???
If AMSAT asks for volunteers its usually for newsletters, booth duty or web site maintenance. The AMSAT BoD raises money, provides it to groups doing development of amateur satellites and provides general services like this mailing list. In my experience, satellites are developed by dedicated teams that will ask for volunteers for specific tasks. For example, I was a volunteer for Eagle U-band receiver development. AMSAT might have passed on a name and the position had already been filled. 73, John KD6OZH - Original Message - From: "Tom Lubbers K8TL" To: "AMSAT BB" Sent: Friday, June 07, 2013 15:55 UTC Subject: [amsat-bb] AMSAT needs volunteers ??? Over the past half century I responded several times to AMSAT’s call for volunteers and never heard back from them. I was happy to hear from my son when he volunteered his software talents to AMSAT and told me that they had asked when would be a good time to contact him. His job title is Software Engineer with over 30 years experience, a number of published articles and winner of a number of design contests. He is also comfortable with hardware and firmware. If I mention a piece of hardware or software that I wish was a available in my ham shack it is usually available the next time he visits. Oh by the way I see AMSAT is still looking for a software guy, they never followed up on their request of when they could contact him. They sure blew an opportunity there. Tom K8TL ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
[amsat-bb] Re: 2.4GHz broadband router on satellite?
Yes, 2.4 GHz was very noisy. AMSAT Eagle was to use a 3.4 GHz high-speed (0.5-1 Mbps) BPSK downlink. BPSK was chosen for maximum efficiency in the PA. WiFi and WiMAX use complex modulation schemes that are optimized for terrestrial applications where the signal is diffused and scattered by nearby objects. This results in a PA DC to RF conversion efficiency of less than 20%. 73, John KD6OZH - Original Message - From: "Mark L. Hammond" To: "Trevor ." Cc: "amsat-bb" Sent: Friday, February 22, 2013 16:20 UTC Subject: [amsat-bb] Re: 2.4GHz broadband router on satellite? Maybe Drew KO4MA will reply--but I thought he did some "global listening" on 2.4GHz with AO-51 (frequency agile receiver). Seems like he published some plots in The Journal? Take home from what I recall--it was very noisy! Mark N8MH On Fri, Feb 22, 2013 at 10:49 AM, Trevor . wrote: Apart from power budget issues and Doppler the real killer will be the very high noise level on 2.4 GHz. In urban areas you can expected to receive strong WiFi signals across all of 2402-2450 almost regardless of where you beam. Any signals from a satellite would need to be strong enough to overcome this interference. 5 GHz is likely to suffer a similar problem in a few years as more use is made of that band for WiFi etc. 73 Trevor M5AKA ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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] ___ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. 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@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb