Ham Talk Live! Episode 205 - New Radio on the Space Station

Hahaha Yeah I had the same thought!

 

Well, for one, Kenwood is an ARISS sponsor, so I doubt they'd run out to HRO and pick up a 9700.

But more importantly, I think the idea is to provide a robust solution with the least amount of "buttons". Thus, a mobile unit (designed for the rough environment of a car, with vibrations, temp changes, etc.) with hardcoded modes (less chance for an astro/cosmonaut to push the wrong button).

 

Well, I expect that they'll be using the rig with a computer, which means that they could put in hardcoded programs for different tasks (such as school contacts). And most modern rigs are plenty rugged enough for the job.

The Kenwood isn't a bad radio, but due to its limitations they'll miss out on a few key capabilities such as SSB (a very popular mode for UHF/VHF simplex communications) and weak signal digital modes. (It'd be wonderful if they operated FT4, which could do lots and lots of very quick QSOs with grateful hams during a pass.) And they won't have a bandscope. So it may, alas, be a matter of manufacturer preference rather than choosing the best rig for the job.

 

There have been a minimum of 2 working ham radios on the ISS for, like, 20 years... and only a very small number of people outside of ARISS school contacts have been lucky enough to score a direct QSO with an astronaut (myself included).... do you really think astronauts are going to take the time to set up SSB or digital mode contacts? Sure, in a perfect world, but in a realistic world the transceiver they got is 10x better than what they have and what they "need" it for.

 

Why not? It gets lonely up there, and historically, astronauts have often made ham radio contacts after working hours. Astronauts are, naturally, science geeks. Why not encourage them to explore the latest technology and engage in more modes of communication, rather than restricting them to a radio with limited capabilities? SSB is available with one click of the dial - not on that rig, but on many - and digital modes require just firing up a program on a laptop. I think it'd be amazing for all concerned if the astronauts worked a digital mode (which, yes, would require SSB because the FM "capture effect" prevents superposition and thus rules out many of them).

 

What's DPRS got to do with anything?

 

Often? I can only think of two..... Doug Wheelock and Serena Aunon-Chancellor. My contact was with Serena at the end of 2018 - when she would make contacts on Saturday morning passes (she did it for a few weeks only). I know Doug made much more, but he was also much farther back. We went something like 5 or 10 years between the two when there were NO one-on-one contacts made (except for the odd ARISS arranged test contacts).

Edit: How would the modern digital modes handle doppler?

 

Doug Wheelock, whom I met when Tom Medlin hosted him in his booth at Dayton last summer, was indeed quite prolific. But hams have mentioned to me that they've had recreational contacts from astronauts not mentioned above - I didn't take down the names, but I know it wasn't the two above. I'll wager that if the radio was fun to play with, with more modes and the ability to do lots of contacts in a short period of time, they'd probably use it much more during their free time!

As for digital modes and doppler shift: the advantage of the latest digital mode software is that is takes in a large portion of the band at once and decodes everything it sees, so there's no need to retune. And the protocols build recalibration sequences right into the packets. So, they're ideal. You can concentrate on communication rather than on retuning.

 

Ok, well..... unfortunately that proves my point. Doug and Serena were the only two who made enough contacts to be notable. Any others were few and far between.

I don't think it's as easy as you make it sound. An FT8 signal is, what, 50 Hz? Doppler shift, even at 10m - could swing at least 1 kHz...

 

You're conflating bandwidth with center frequency. The center frequency won't shift that quickly, and so long as it remains within roughly a 2.8 KHz range the software can track it.

 

I'm not conflating anything. I may be incorrect, but I'm not conflating bandwidth and center frequency. Are you telling me that WSJT-X can shift both the send and receive frequency (shift the af frequency, not the rf frequency) up to a khz in the middle of a send receive cycle? If yes, then I am incorrect. I've just heard so much about the newer digital modes requiring rock solid (steady) tuners or else the modes weren't possible. That may have changed or may never have been the case.

I stand by my statement that if astronauts can't be bothered to make a few voice qso's, then they certainly aren't going to bother with digital modes, though. 'nuff said.

 

There are lots of spare laptops floating around in the ISS. And of course the guys running 1500 watts into an array could make some difficult and amazing contacts with the astronauts on FT4. Just as they make amazing contacts here on mother earth. What a challenge it would be for everyone. For sure it would keep the astronauts from getting so lonely in space.

 

When does it ever bother a computer to make a contact with another computer? I must be missing something important here...

I am running FT4 on a 25 year old computer without a "rock solid (steady) tuner." The only problem I have ever had is with the clock being off by a few microseconds. But free software corrects that very easily. Maybe my computer just couldn't be bothered to run Meinberg because it was fretting over my "not rock solid tuner."

 

Absolutely nothing.

 

I`m a young guy and i just know that the biggest radio company who work for space systems is motorola but now i heard something about Hytera radio systems not about space but ethernet connections .