Date   
Re: Bill you missed out on a business opportunity

Jayant Murthy
 

Thanks for writing this. I feel that many of the "new space" people are more caught up with cool than needed.
Jayant

On Thursday, February 14, 2019, 8:49:44 AM GMT+5:30, Bill Brown via Groups.Io <wb8elk@...> wrote:


As often is the case, the pioneers in technology are too far in advance of demand. All I see here is a small rocket launched from a not-very-high hot air balloon. I do wish them success and hopefully they have worked out the math for the optimum liftoff altitude and rocket thrust (and weight) necessary to achieve orbit. There have been dozens of Rockoon startups with fancy CGI graphics, a nicely edited video and great background music who then disappear when they find funding is hard to raise. A hot-air-balloon (or high-altitude zero pressure balloon) would have to be capable of lifting thousands of pounds of rocket to place a small toaster-size payload into LEO orbit and would have to be above 70,000 feet to make it worthwhile. A rockoon is indeed a great first stage replacement. The rocket can be about 25 percent of the weight of an equivalent ground-based launch plus the rocket motor nozzle is more efficient in a near vacuum BUT it is also much harder to ignite in a near vacuum and -60 deg temperatures. We did work out how to do that using a series of weather balloon flights. A small rocket can make it into Space itself but it would come right back down again. Very useful for microgravity and sounding rocket experiments. Plus it gives you the flexibility of moving your launchsite around on a boat which we proved out 20 years ago since you can cancel out the surface winds completely by steering the boat along with the wind (up to the speed limitation of the boat). James Van Allen sent some of his rockoons thousands of miles into Space but didn't achieve orbital velocity and he also did most of his flights from the decks of Navy ships. That's where you need a much heavier rocket to achieve orbit, even with a Rockoon.

They seem to imply that they will be using a hot air balloon at 58,000 feet to launch their rockoon. While I was at the NearSpace Conference in Poland I had to pleasure to hear a talk about a fellow who took a hot-air balloon to 32,000 feet and beyond. It took an enormous redesign of their propane burners to work at that altitude and even after all their design efforts they still failed to keep burning after they got close to their altitude goal. I did find a story about a balloon pilot in India who made it to 69850 feet but the hot air balloon envelope was enormous and likely not capable of lifting thousands of pounds of rocket in addition.

The available launchsites for a Rockoon are very limited. Basically Black Rock Desert in Nevada, Spaceport America in New Mexico, some of the larger military bases and even a possibility in Sheboygan WI across Lake Michigan. However you cannot go past the range limits which is a real problem for a high altitude balloon and even worse you would have to prove that your rocket will land within the range after going into Space and back if it fails to achieve orbit. We solved that problem by heading out to sea on a large oil supply boat and had to be 200 miles from the coastline to launch the rocket. And yes we had FAA permission and also had to coordinate with the Coast Guard, the Navy and the Air Force. It actually took longer to get permission from all of these agencies than it did to design and build the Rockoon system. We flew a 400 pound rocket from a 500,000 cubic foot Raven zero-pressure balloon....it took 33 tanks of helium.

 So it boils down to whether a hot air balloon of that magnitude and flight logistics combined with the range limitations is a cost effective way to launch small satellites with a 25 percent lighter-weight rocket than a ground-based rocket. 

- Bill WB8ELK


-----Original Message-----
From: Zack Clobes W0ZC <zclobes@...>
To: GPSL <GPSL@groups.io>
Sent: Wed, Feb 13, 2019 6:02 pm
Subject: [GPSL] Bill you missed out on a business opportunity

Re: Bill you missed out on a business opportunity

rellekevets@...
 

Bill,

Thank you for the write up. Enthralling read!

Steve
AE8AT

New bumper sticker

L. Paul Verhage KD4STH
 

I came up with a new ARHAB bumper sticker idea during dinner at Blaze Pizza.


Re: New bumper sticker

Bill Brown
 

Maybe change it to "Keeping your head above the clouds since 1987". -Bill WB8ELK


On Feb 14, 2019, at 9:29 PM, L. Paul Verhage KD4STH <nearsys@...> wrote:

I came up with a new ARHAB bumper sticker idea during dinner at Blaze Pizza.


<head in the clouds.JPG>

Re: New bumper sticker

L. Paul Verhage KD4STH
 

Like it.


On Fri, Feb 15, 2019, 3:04 PM Bill Brown via Groups.Io <wb8elk=aol.com@groups.io> wrote:
Maybe change it to "Keeping your head above the clouds since 1987". -Bill WB8ELK


On Feb 14, 2019, at 9:29 PM, L. Paul Verhage KD4STH <nearsys@...> wrote:

I came up with a new ARHAB bumper sticker idea during dinner at Blaze Pizza.


<head in the clouds.JPG>

APRS Setup

Keith Kaiser, WA0̷TJT
 

Hi guys!

I’ve been out of the loop for a while … I hope someone notices… LOL

I’m trying to set up a TinyTrack3Plus with a Baofeng UV-3R but I’m not having much success.I can see the red light coming on indicating the TinyTrack is transmitting. I can see the radio going into transmit mode occasionally but the two are not happing at the same time. I’m guessing that means I have the VOX in the radio set wrong or I have one of the many settings in the TT3 set wrong. 

Would one of you maybe walk through the settings for both so I can get this pair working?

Thanks… see you all in Pella.

Keith, WA0̷TJT



Exploding Balloons

L. Paul Verhage KD4STH
 

Looking for Speakers for the BalloonSat Forum at the Dayton Hamvention

Bill Brown
 

If any of you who will be attending the Dayton Hamvention this year would like to give a 25 minute talk at the BalloonSat Forum  (Friday of the HAmvention), please contact me.

- Bill WB8ELK

WB8ELK at AOL dot com

Frequency selection for airborne crossband repeaters

Michael Hojnowski
 

Hey Gang,

I'm intending to fly a cross-band repeater with a HAB in April.  It occurs to me that I don't have a good idea of how to select frequencies.  Should I be using one from the repeater input range on one band, and output on another?  Should I be selecting simplex frequencies for this short term use?  Should I attempt any kind of coordination with our regional frequency coordination groups?

What have people done?

Thanks for any advice,
Mike / KD2EAT

Re: Frequency selection for airborne crossband repeaters

Mark Conner N9XTN
 

We have flown simplex repeaters before (record and rebroadcast).  At first we used 446.00, figuring people would be pleasantly surprised by having a long-distance balloon contact.  Not so much.  We then tried 446.10 and found another somewhat regular user.  We since settled on 446.30 for our ground and airborne comms.

I've also flown SSTV on 147.585 without any complaints.

A freq council might be able to let you know if certain simplex freqs are in use for other purposes.  For example, one of the local repeaters used to have an auxiliary input frequency in the 147.4ish range.  

73 de Mark N9XTN

On Wed, Feb 27, 2019 at 8:40 AM Michael Hojnowski <kd2eat@...> wrote:
Hey Gang,

I'm intending to fly a cross-band repeater with a HAB in April.  It
occurs to me that I don't have a good idea of how to select
frequencies.  Should I be using one from the repeater input range on one
band, and output on another?  Should I be selecting simplex frequencies
for this short term use?  Should I attempt any kind of coordination with
our regional frequency coordination groups?

What have people done?

Thanks for any advice,
Mike / KD2EAT



Re: Frequency selection for airborne crossband repeaters

Bill Brown
 

I typically use 446.025 and 144.340. Both are simplex. For a simplex repeater i use 144.340.
-Bill WB8ELK

On Feb 27, 2019, at 8:39 AM, Michael Hojnowski <kd2eat@...> wrote:

Hey Gang,

I'm intending to fly a cross-band repeater with a HAB in April. It occurs to me that I don't have a good idea of how to select frequencies. Should I be using one from the repeater input range on one band, and output on another? Should I be selecting simplex frequencies for this short term use? Should I attempt any kind of coordination with our regional frequency coordination groups?

What have people done?

Thanks for any advice,
Mike / KD2EAT


Re: Frequency selection for airborne crossband repeaters

Joe WB9SBD
 

I agree with Bill on that Pairing.

FORGET repeater co-coordinators. We used them on the very first repeater flight ever.Way back in like 1989 or so. And They just do not understand the coverages we can get with these flights. And one of the UHF freqs we were suggested to use as being safe, ended up being a UHF link from a repeater system, satellite receivers. So in the middle of our flight, suddenly on the balloon was a swapnet happening.

But if you want quiet great freq the pair Bill stated below we have used probably a dozen times and have worked great every time.

Now if you really want to have FUN! Many will make me now to put on my Flame suit. But we have done it probably 4 times? But the biggest fun was this pair
 146.52/446.000  Yup! It was crazy easily worked well over 300+ stations!

Mike what do you plan on usi9ng for equipment?

Will the repeater go both ways, think HT in crossband repeat but both directions.

Joe WB9SBD
KB9KHO
Near Space Sciences

The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com

On 2/27/2019 9:59 AM, Bill Brown via Groups.Io wrote:
I typically use 446.025 and 144.340. Both are simplex. For a simplex repeater i use 144.340. 
-Bill WB8ELK
On Feb 27, 2019, at 8:39 AM, Michael Hojnowski <kd2eat@...> wrote:

Hey Gang,

I'm intending to fly a cross-band repeater with a HAB in April.  It occurs to me that I don't have a good idea of how to select frequencies.  Should I be using one from the repeater input range on one band, and output on another?  Should I be selecting simplex frequencies for this short term use?  Should I attempt any kind of coordination with our regional frequency coordination groups?

What have people done?

Thanks for any advice,
Mike / KD2EAT









Re: Frequency selection for airborne cross band repeaters

Barry
 

A couple of things come to mind.

The most important choice is the input freq as, not long after you launch, you'll be receiving any/all transmissions within hundreds of miles with no easy way to contact those making the transmissions to explain the situation and ask them to move to a different freq which means the cross-band repeater will basically become useless. Therefore I would stay away from using a repeater freq unless you are 100% sure there aren't any using your chosen input freq as either an input or output freq. For the same reason you should avoid using the simplex calling freq or any other simplex freq that some group may have chosen to use for their simplex conversations. This may be hard to determine and you'll have to simply ask around and hope for the best. Anyway, in the past we have always used a UHF simplex freq several channels away from the calling freq as UHF basically eliminated the chance of having a problem with our APRS VHF transmissions affecting the cross band receiver plus we would have much less UHF simplex activity to worry about. Therefore our cross band transmissions had to be VHF which was preferred as many more amateurs have VHF transceivers than UHF and allowed more to participate (even though simply by listening).

The output freg is not nearly as important as anyone that may be on the freq can/will simply move to a free channel. Most are quite forgiving (or should be) and after hearing a few cross band transmissions will likely realize what's going on, especially if there's a control operator, like we had, that regularly explains the situation and the input freq being used for anyone listening that may want to join in on the fun. (I believe we reached about 100,000ft and our furthest contact was from about 600 miles away. I'm pretty sure there aren't any unused VHF repeater freq's that could have been used and guessing the situation is most likely the same just about anywhere in the US.).

Barry - VE6SBS

-----Original Message-----
From: GPSL@groups.io [mailto:GPSL@groups.io] On Behalf Of Michael Hojnowski
Sent: Wednesday, February 27, 2019 7:40 AM
To: GPSL list
Subject: [GPSL] Frequency selection for airborne crossband repeaters

Hey Gang,

I'm intending to fly a cross-band repeater with a HAB in April. It
occurs to me that I don't have a good idea of how to select
frequencies. Should I be using one from the repeater input range on one
band, and output on another? Should I be selecting simplex frequencies
for this short term use? Should I attempt any kind of coordination with
our regional frequency coordination groups?

What have people done?

Thanks for any advice,
Mike / KD2EAT

Re: Frequency selection for airborne crossband repeaters

Michael Hojnowski
 

Well, I pulled the spreadsheet kept by the Upstate New York Repeater coordinators, and found a few frequencies that seem clear - 144.580 input, 447.025 output. 

I'm going to try a few NiceRF SA828 Walkie Talkie modules.  Not sure if I'll run them at 500mW or 1W.   Since it'll be transmitting on 70cm, I'm inclined to use the lower power, since it'll have lower free space path loss.  That would also reduce battery drain.

This is going to be an ambitious flight, including analog TV video on 70cm, the repeater, a payload drop initiated via DTMF tones, and with luck, the entire thing livestreamed onto youtube.  We hope to have a ground station with a high gain beam tracking based on APRS beacons, and feeding into the youtube stream.  

Bill / WB8ELK has me on the agenda to talk about the successes (or spectacular "lessons learned") at the Balloon Sat session at Dayton.

As the flight draws near, and we're confident we can livestream, I'll post URLs for those who would like to watch at home.  Tentative flight date is Sunday, April 28 with a rain date on May 5.

Mike / KD2EAT
Advisor, Amateur Radio Club at Cornell


On 2/27/2019 12:23 PM, Joe wrote:
I agree with Bill on that Pairing.

FORGET repeater co-coordinators. We used them on the very first repeater flight ever.Way back in like 1989 or so. And They just do not understand the coverages we can get with these flights. And one of the UHF freqs we were suggested to use as being safe, ended up being a UHF link from a repeater system, satellite receivers. So in the middle of our flight, suddenly on the balloon was a swapnet happening.

But if you want quiet great freq the pair Bill stated below we have used probably a dozen times and have worked great every time.

Now if you really want to have FUN! Many will make me now to put on my Flame suit. But we have done it probably 4 times? But the biggest fun was this pair
 146.52/446.000  Yup! It was crazy easily worked well over 300+ stations!

Mike what do you plan on usi9ng for equipment?

Will the repeater go both ways, think HT in crossband repeat but both directions.

Joe WB9SBD
KB9KHO
Near Space Sciences

The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com

On 2/27/2019 9:59 AM, Bill Brown via Groups.Io wrote:
I typically use 446.025 and 144.340. Both are simplex. For a simplex repeater i use 144.340. 
-Bill WB8ELK
On Feb 27, 2019, at 8:39 AM, Michael Hojnowski <kd2eat@...> wrote:

Hey Gang,

I'm intending to fly a cross-band repeater with a HAB in April.  It occurs to me that I don't have a good idea of how to select frequencies.  Should I be using one from the repeater input range on one band, and output on another?  Should I be selecting simplex frequencies for this short term use?  Should I attempt any kind of coordination with our regional frequency coordination groups?

What have people done?

Thanks for any advice,
Mike / KD2EAT








Re: Frequency selection for airborne crossband repeaters

Bill Brown
 

I would go with the 500 mW setting since it will likely have a high duty cycle and could overheat, even at 500 mW it could still overheat so try to mount the module on a good heatsink. Since you are running ATV on 70cm, you will want to transmit the crossband repeater on 70cm as well otherwise the receiver will be desensed by ATV EMI hash. But be aware to keep good separation between the ATV payload and the crossband repeater since you could see interference from the ATV transmitter getting into the 2m receiver as well. Perhaps a low-pass filter or bandpass filter in front of the receiver module would be a good idea. Also be aware that the ATV transmitter and camera could desense GPS receivers so also keep separation between the ATV payload and your balloon trackers.

- Bill WB8ELK

I would agree with other posts on this topic that it is best to stay with simplex frequencies. That's why I always fly with 446.025 out and 144.340 input or vice versa. The 446.025 frequency is not used a lot as compared to 446.000...although 445.975 and 446.300 are good alternates. Same for 144.340. It is primarily used nation-wide as an ATV talk frequency and occasionally for APRS links for balloon flights. The ATV folks don't mind and love to follow balloon flights and particularly appropriate in this case since you are flying an ATV transmitter. Even if someone is using 144.340 and not following your balloon, it won't matter since you won't interfere with them. I did fly a crossband repeater years ago from 73 Magazine headquarters in NH with 446.000 as the input and a 25 milliwatt 10m FM transmitter as the output during the VHF/UHF contest. It was a blast hearing all the mountaintop rover stations from well beyond typical line-of-sight ranges. Yes, that's right I used 10m as the output. It is legal to do so in the FM portion of 10m.








-----Original Message-----
From: Michael Hojnowski <kd2eat@...>
To: GPSL <GPSL@groups.io>
Sent: Wed, Feb 27, 2019 12:12 pm
Subject: Re: [GPSL] Frequency selection for airborne crossband repeaters

Well, I pulled the spreadsheet kept by the Upstate New York Repeater coordinators, and found a few frequencies that seem clear - 144.580 input, 447.025 output. 

I'm going to try a few NiceRF SA828 Walkie Talkie modules.  Not sure if I'll run them at 500mW or 1W.   Since it'll be transmitting on 70cm, I'm inclined to use the lower power, since it'll have lower free space path loss.  That would also reduce battery drain.

This is going to be an ambitious flight, including analog TV video on 70cm, the repeater, a payload drop initiated via DTMF tones, and with luck, the entire thing livestreamed onto youtube.  We hope to have a ground station with a high gain beam tracking based on APRS beacons, and feeding into the youtube stream.  

Bill / WB8ELK has me on the agenda to talk about the successes (or spectacular "lessons learned") at the Balloon Sat session at Dayton.

As the flight draws near, and we're confident we can livestream, I'll post URLs for those who would like to watch at home.  Tentative flight date is Sunday, April 28 with a rain date on May 5.

Mike / KD2EAT
Advisor, Amateur Radio Club at Cornell


On 2/27/2019 12:23 PM, Joe wrote:
I agree with Bill on that Pairing.

FORGET repeater co-coordinators. We used them on the very first repeater flight ever.Way back in like 1989 or so. And They just do not understand the coverages we can get with these flights. And one of the UHF freqs we were suggested to use as being safe, ended up being a UHF link from a repeater system, satellite receivers. So in the middle of our flight, suddenly on the balloon was a swapnet happening.

But if you want quiet great freq the pair Bill stated below we have used probably a dozen times and have worked great every time.

Now if you really want to have FUN! Many will make me now to put on my Flame suit. But we have done it probably 4 times? But the biggest fun was this pair
 146.52/446.000  Yup! It was crazy easily worked well over 300+ stations!

Mike what do you plan on usi9ng for equipment?

Will the repeater go both ways, think HT in crossband repeat but both directions.

Joe WB9SBD
KB9KHO
Near Space Sciences

The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com

On 2/27/2019 9:59 AM, Bill Brown via Groups.Io wrote:
I typically use 446.025 and 144.340. Both are simplex. For a simplex repeater i use 144.340. 
-Bill WB8ELK
On Feb 27, 2019, at 8:39 AM, Michael Hojnowski <kd2eat@...> wrote:

Hey Gang,

I'm intending to fly a cross-band repeater with a HAB in April.  It occurs to me that I don't have a good idea of how to select frequencies.  Should I be using one from the repeater input range on one band, and output on another?  Should I be selecting simplex frequencies for this short term use?  Should I attempt any kind of coordination with our regional frequency coordination groups?

What have people done?

Thanks for any advice,
Mike / KD2EAT







Re: Frequency selection for airborne crossband repeaters

Joe WB9SBD
 

Mike,
As I and others have stated forget about the repeater co-oridinators. You say up state NY. how about 600 miles away? or at least 3 to 4 hundred because that is what your balloon will be hearing.

Get on line and look for a old Wyman Research ATV transmitter. I got two, (and no I will not ever let them go)

Reason is his transmitters are two for the price of 1 and battery budget because while he has the typical ATV signal AM on say 439.250 MHz, and the audio sub carrier. at 3 watts or so.

BUT he does magic! He FM Modulates the AM carrier also, so not only do you have the ATV signal. but a 3 watt 5 KHz FM signal for your cross band repeater transmitter!

Joe WB9SBD

The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com

On 2/27/2019 12:11 PM, Michael Hojnowski wrote:
Well, I pulled the spreadsheet kept by the Upstate New York Repeater coordinators, and found a few frequencies that seem clear - 144.580 input, 447.025 output. 

I'm going to try a few NiceRF SA828 Walkie Talkie modules.  Not sure if I'll run them at 500mW or 1W.   Since it'll be transmitting on 70cm, I'm inclined to use the lower power, since it'll have lower free space path loss.  That would also reduce battery drain.

This is going to be an ambitious flight, including analog TV video on 70cm, the repeater, a payload drop initiated via DTMF tones, and with luck, the entire thing livestreamed onto youtube.  We hope to have a ground station with a high gain beam tracking based on APRS beacons, and feeding into the youtube stream.  

Bill / WB8ELK has me on the agenda to talk about the successes (or spectacular "lessons learned") at the Balloon Sat session at Dayton.

As the flight draws near, and we're confident we can livestream, I'll post URLs for those who would like to watch at home.  Tentative flight date is Sunday, April 28 with a rain date on May 5.

Mike / KD2EAT
Advisor, Amateur Radio Club at Cornell


On 2/27/2019 12:23 PM, Joe wrote:
I agree with Bill on that Pairing.

FORGET repeater co-coordinators. We used them on the very first repeater flight ever.Way back in like 1989 or so. And They just do not understand the coverages we can get with these flights. And one of the UHF freqs we were suggested to use as being safe, ended up being a UHF link from a repeater system, satellite receivers. So in the middle of our flight, suddenly on the balloon was a swapnet happening.

But if you want quiet great freq the pair Bill stated below we have used probably a dozen times and have worked great every time.

Now if you really want to have FUN! Many will make me now to put on my Flame suit. But we have done it probably 4 times? But the biggest fun was this pair
 146.52/446.000  Yup! It was crazy easily worked well over 300+ stations!

Mike what do you plan on usi9ng for equipment?

Will the repeater go both ways, think HT in crossband repeat but both directions.

Joe WB9SBD
KB9KHO
Near Space Sciences

The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com

On 2/27/2019 9:59 AM, Bill Brown via Groups.Io wrote:
I typically use 446.025 and 144.340. Both are simplex. For a simplex repeater i use 144.340. 
-Bill WB8ELK
On Feb 27, 2019, at 8:39 AM, Michael Hojnowski <kd2eat@...> wrote:

Hey Gang,

I'm intending to fly a cross-band repeater with a HAB in April.  It occurs to me that I don't have a good idea of how to select frequencies.  Should I be using one from the repeater input range on one band, and output on another?  Should I be selecting simplex frequencies for this short term use?  Should I attempt any kind of coordination with our regional frequency coordination groups?

What have people done?

Thanks for any advice,
Mike / KD2EAT







Re: Frequency selection for airborne crossband repeaters

Joe WB9SBD
 

Also since you are running ATV, if you are flying a GPS unit, try to separate it as far as possible from the ATV system, I have had both the transmitters and even just the video cameras desence the GPS so much it was useless.

Joe WB9SBD

The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com

On 2/27/2019 12:52 PM, Bill Brown via Groups.Io wrote:
I would go with the 500 mW setting since it will likely have a high duty cycle and could overheat, even at 500 mW it could still overheat so try to mount the module on a good heatsink. Since you are running ATV on 70cm, you will want to transmit the crossband repeater on 70cm as well otherwise the receiver will be desensed by ATV EMI hash. But be aware to keep good separation between the ATV payload and the crossband repeater since you could see interference from the ATV transmitter getting into the 2m receiver as well. Perhaps a low-pass filter or bandpass filter in front of the receiver module would be a good idea. Also be aware that the ATV transmitter and camera could desense GPS receivers so also keep separation between the ATV payload and your balloon trackers.

- Bill WB8ELK

I would agree with other posts on this topic that it is best to stay with simplex frequencies. That's why I always fly with 446.025 out and 144.340 input or vice versa. The 446.025 frequency is not used a lot as compared to 446.000...although 445.975 and 446.300 are good alternates. Same for 144.340. It is primarily used nation-wide as an ATV talk frequency and occasionally for APRS links for balloon flights. The ATV folks don't mind and love to follow balloon flights and particularly appropriate in this case since you are flying an ATV transmitter. Even if someone is using 144.340 and not following your balloon, it won't matter since you won't interfere with them. I did fly a crossband repeater years ago from 73 Magazine headquarters in NH with 446.000 as the input and a 25 milliwatt 10m FM transmitter as the output during the VHF/UHF contest. It was a blast hearing all the mountaintop rover stations from well beyond typical line-of-sight ranges. Yes, that's right I used 10m as the output. It is legal to do so in the FM portion of 10m.








-----Original Message-----
From: Michael Hojnowski <kd2eat@...>
To: GPSL <GPSL@groups.io>
Sent: Wed, Feb 27, 2019 12:12 pm
Subject: Re: [GPSL] Frequency selection for airborne crossband repeaters

Well, I pulled the spreadsheet kept by the Upstate New York Repeater coordinators, and found a few frequencies that seem clear - 144.580 input, 447.025 output. 

I'm going to try a few NiceRF SA828 Walkie Talkie modules.  Not sure if I'll run them at 500mW or 1W.   Since it'll be transmitting on 70cm, I'm inclined to use the lower power, since it'll have lower free space path loss.  That would also reduce battery drain.

This is going to be an ambitious flight, including analog TV video on 70cm, the repeater, a payload drop initiated via DTMF tones, and with luck, the entire thing livestreamed onto youtube.  We hope to have a ground station with a high gain beam tracking based on APRS beacons, and feeding into the youtube stream.  

Bill / WB8ELK has me on the agenda to talk about the successes (or spectacular "lessons learned") at the Balloon Sat session at Dayton.

As the flight draws near, and we're confident we can livestream, I'll post URLs for those who would like to watch at home.  Tentative flight date is Sunday, April 28 with a rain date on May 5.

Mike / KD2EAT
Advisor, Amateur Radio Club at Cornell


On 2/27/2019 12:23 PM, Joe wrote:
I agree with Bill on that Pairing.

FORGET repeater co-coordinators. We used them on the very first repeater flight ever.Way back in like 1989 or so. And They just do not understand the coverages we can get with these flights. And one of the UHF freqs we were suggested to use as being safe, ended up being a UHF link from a repeater system, satellite receivers. So in the middle of our flight, suddenly on the balloon was a swapnet happening.

But if you want quiet great freq the pair Bill stated below we have used probably a dozen times and have worked great every time.

Now if you really want to have FUN! Many will make me now to put on my Flame suit. But we have done it probably 4 times? But the biggest fun was this pair
 146.52/446.000  Yup! It was crazy easily worked well over 300+ stations!

Mike what do you plan on usi9ng for equipment?

Will the repeater go both ways, think HT in crossband repeat but both directions.

Joe WB9SBD
KB9KHO
Near Space Sciences

The Original Rolling Ball Clock
Idle Tyme
Idle-Tyme.com
http://www.idle-tyme.com

On 2/27/2019 9:59 AM, Bill Brown via Groups.Io wrote:
I typically use 446.025 and 144.340. Both are simplex. For a simplex repeater i use 144.340. 
-Bill WB8ELK
On Feb 27, 2019, at 8:39 AM, Michael Hojnowski <kd2eat@...> wrote:

Hey Gang,

I'm intending to fly a cross-band repeater with a HAB in April.  It occurs to me that I don't have a good idea of how to select frequencies.  Should I be using one from the repeater input range on one band, and output on another?  Should I be selecting simplex frequencies for this short term use?  Should I attempt any kind of coordination with our regional frequency coordination groups?

What have people done?

Thanks for any advice,
Mike / KD2EAT




                    



Re: Frequency selection for airborne cross band repeaters

Carlton Corbitt
 

One thing i think works well, if you are part of a ham club that has a working repeater.   Is to put your balloon repeater output frequency the same as your clubs repeater output frequency.  That way everyone has the output frequency already programmed into the mobile radios to listen while tracking.
And you should be able to know if your own clubs repeater is planning to be in use or not.

Carlton
KI4NHK

LightAPRS Tracker

Mustafa Tan
 

Hi,

Three years ago I was googling about high altitude balloons and I ended up with pico (floater) balloon projects. I was really impressed with some amateur radio operators efforts to circumnavigate around the world with party balloons and track them.

Six months later I got my amateur radio license and started flights with heavy APRS trackers. Since payload is very heavy, balloons maximum altitude never exceeded 9.000 meters and modules I used was not frequency agile.

So we (TA2MUN and TA9OHC) decided to develop a lightweight, extendable, affordable and open source APRS tracker. Since our tracker is very light and frequency agile, it's very convenient for pico (floater) balloon and HAB (High Altitude Balloon) projects. LightAPRS Tracker has been developed for nearly two years now and has been proven on many flights.

You can check out our tracker using following links:

Github page : https://github.com/lightaprs/LightAPRS-1.0
Shop : http://www.qrp-labs.com/lightaprs.html

Please do not hesitate to share if you have questions or comments about our tracker 

TA2MUN

GPS Rollover

Harry M