FW: [FWD: RE: Southern CA Satellite Presentations]
Then what I am hearing, "AS A NEWBIE" is that I am not welcome on the Sats because I do not have the financial resources to invest in all the equipment needed to run full duplex. It is more than two cheap Chinese radios, it also involves an antenna, which at the very least it is almost double the cost of the two Chinese radios.
Money that some of us have a hard time pulling together.
I have a hard time with all the purest, my way or the highway mentality I am hearing.
Just my 2 cents
Jerry W4JWC
-------- Original Message -------- Subject: Re: [amsat-bb] Southern CA Satellite Presentations From: Michael <Mat_62@charter.net mailto:Mat_62@charter.net > Date: Mon, June 27, 2016 9:04 pm To: amsat-bb@amsat.org mailto:amsat-bb@amsat.org
I could care less whether you have ever uttered it or not in one of your live presentations. It is printed in black and white in your handout. You just quoted it yourself. The minute you typed that phrase and began giving out handouts or telling people to print it out you became guilty of spreading ignorance as far as satellite operation is concerned. You are leading newbie sat operators down a path they should not be on. If one does not have the means to hear their own signal coming back from the bird so as to insure they are "making it there" then they should not be on the satellites. End of story. Michael, W4HIJ On 6/26/2016 11:37 PM, Clint Bradford wrote:
... you would quit telling people that full duplex is "not mandatory" for working sats.
You've never attended one of my sat sessions. I have never uttered the sentence to groups, "It is not mandatory to work full-duplex. - PERIOD." My standard mantra for the easy FM birds is all over the place:
"Ideally, we should be working the satellites in full duplex mode, where we can simultaneously listen to the downlink as we are transmitting. Although this method is preferred, it is not mandatory: Carefully monitor the downlink, and wait for a break in the conversations to announce yourself."
People you might be hearing stepping on others are not following those instructions.
And all my audiences are very graphically shown and told the reasons why working full- duplex is preferable.
I didn't work full-duplex when speaking with Commander Wiseman - who was aboard the ISS at the time during Field Day 2014.
If you haven't already given a presentation to your club on working the easy birds, I am available. Just send me an email message.
Clint Bradford K6LCS (909) 999-SATS _______________________________________________ Sent via AMSAT-BB@amsat.org mailto:AMSAT-BB@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://www.amsat.org/mailman/listinfo/amsat-bb
_______________________________________________ Sent via AMSAT-BB@amsat.org mailto:AMSAT-BB@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://www.amsat.org/mailman/listinfo/amsat-bb
On Tue, Jun 28, 2016 at 9:42 AM, Jerry Conner via AMSAT-BB amsat-bb@amsat.org wrote:
Then what I am hearing, "AS A NEWBIE" is that I am not welcome on the Sats because I do not have the financial resources to invest in all the equipment needed to run full duplex. It is more than two cheap Chinese radios, it also involves an antenna, which at the very least it is almost double the cost of the two Chinese radios.
I think I paid $150-something for my Arrow II with the diplexer (because I only use one radio) so yeah about the price of two cheap Chinese HTs.
There is nothing stopping anyone from building an entirely adequate antenna themselves. See, for example, http://www.wa5vjb.com/references.html .
SO-50, with the FM uplink on 2 m, I don't see much need for full duplex and, in fact, I've had good contacts on a single radio. I can see where AO-85, with the FM uplink on 70 cm having a bigger Doppler swing, that it would be very helpful to have an ear on the downlink. For data, since most digis seem to be on 2m up and down, I don't see the big deal.
On the sats with a linear transponder, it's a different matter since you need to find where you are unless you are using a computer to correct your at-sat frequency.
All that said, if you want this to be a cheap hobby, you're really going to have to work at it.
Jerry Conner said (in part):
I have a hard time with all the purest, my way or the highway mentality
I am hearing.
It's not that it's a elitist mentality, it's simply a technical requirement for successful operation. Even on a FM satellite, operating without full duplex would be about like trying to use your local 2M repeater with a transmitter and no receiver turned on until AFTER you called someone. You have no way of knowing if someone else is talking. Since on most FM satellites, the idle time between conversations is measured in milliseconds, your chances of successfully hitting an idle spot without knowing if your are getting through is quite slim. On SSB or CW on a linear satellite, without full duplex, you will forever be chasing trying to figure out where your downlink is. Even with complete computer control of dopler shift, you will still be chasing the other guy.
On an FM satellite, the situation goes something like this. A contact ends, and for example three people key up to make a call at essentially the same time. Depending on signal levels, maybe one person has a strong enough signal to capture everyone else, but more likely there is a massive hetrodyne between several signals. With everyone operating full duplex, we all hear that either someone else is capturing the uplink or the hetrodyne and drop carrier. If you're not using full duplex, you blindly keep transmitting and creating interference for the rest of the users.
The exception to all this is that if you are operating in a location that has almost no one to talk to (Hawaii comes to mind) since you are almost the only one around, you might get away without full duplex most of the time. A decade or so ago, every night there was a SE to NW pass that was well off the southern California coastline - such that the footprint only covered 50 - 100 miles along the coast. There were a small enough number of us in the footprint that we could actually hold several minute conversations with one or two other people. Non full duplex would likely have worked in that case. However for the previous pass that covered most of the US, I would not have even considered it.
BTW, note that in my first sentence, I said "it's simply a technical requirement for successful operation." The key word there was successful. Without full duplex you will occasionally make a contact (especially as mentioned earlier if you are almost the only person in the footprint), but if you want to routinely be successful on busy passes, there is no alternative to being full duplex. Period.
Jim Walls - K6CCC
participants (3)
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Jerry Conner -
Jim Walls -
Peter Laws