Contacting the ISS and working satellites is a personal goal. I read SO-50 is a good satellite to try first. I’m a little confused. “operating on 145.850 MHz uplink and 436.795 MHz downlink. The repeater is available to amateurs worldwide as power permits, using a 67.0 Hertz PL tone on the uplink, for on-demand activation. SO-50 also has a 10 minute timer that must be armed before use. Transmit a 2 second carrier with a PL tone of 74.4 to arm the timer.” Do I need to program my radio with 7 memories? 1. 145.850 with PL tone 74.4 for activation
2. 145.850 with PL tone 67 for transmitting
3. 435.785 (for doplar shift)
4. 435.790 (for doplar shift)
5. 436.795 for receive
6. 436.800 (for doplar shift)
7. 436.805 (for doplar shift) I’m using a Yaesu FTM-500DR. Is there another way to send the 2 second carrier? I have RT-Systems programmer and it shows Tone Mode options as None, Tone, T Sql, DCS, Rev CTCSS, User CTCSS, Pager, D Code, T DCS, and D Tone. I’m reading manuals but still don’t know what half these tones mean. Is my 1-7 correct? Or am I completely misunderstanding how to work sats? Thank you!
Ok. I think I just answered my own question by actually reading the article the following quote is sourced from. I’m going to post this just in case others have the same question.
TL;DR: Duplexer is the answer.
Diplexers separate signals based on frequency, whereas duplexers separate the transmit and receive path of signals based on their direction. Source: https://resources.pcb.cadence.com/blog/2023-diplexers-vs-duplexers
The Venn diagram in the above source really brings it home. “Duplexers separate the transmit and receive path of signals based on direction”
My confusion started as I was googling around and found this Reddit thread: https://www.reddit.com/r/amateurradio/comments/eq7tal/do_i_need_a_duplexer_for_satellite_work_with_a/ with answers in both directions.
OP asked “Do I need a duplexer for satellite work with a full duplex radio?”
Answers included:
“devices meant […] specifically for separating HF and VHF/UHF”
As the terminology is commonly used, that is a diplexer, not a duplexer.
Then another support for diplexer:
A duplexer (the english speaking world) is a device to combine or split RF paths for a specific frequency, generally in the same band and traditionally use cavity filtering to accomplish this. A diplexer is a device to combine or split frequency ranges of different bands and typically uses a LC filters. The designs come in arrangements of low pass/high pass (diplexer), low pass/band pass/high pass (triplexer), and various low pass/band pass/band pass/…/high pass designs (multiplexers).
The reason you see duplexer often (mistakenly) used in place of diplexer…has to due with the lack of the specific word in the language used in the country the product was manufactured in.
Then the contradiction:
Yes. You need a duplexer to send 70cm to the 70cm side and 2M to 2M.
Along with a link to build duplexers: http://k0lee.com/duplexer.php
And finally, a suggestion to buy a diplexer.
You need a diplexer. Get an MFJ-916.
But the MFJ-916 isn’t a diplexer. It’s a duplexer. https://mfjenterprises.com/products/mfj-916b
The Morserino is a Morse code (CW) trainer. It comes with paddles for training. You can plug in your own straight key or your own paddles. It teaches you cw (morse code) interactively. It has Lora (unlicensed radio frequency) so you can have one Morserino talk to another Morserino if you want to have one person in one room and the training buddy in another room. It connects to the Internet. And it acts as a keyer for radios that do not have a built-in keyer (like most HTs. Technicians can us CW but generally are not equipped for it).
My Morserino arrives at the end of May and I’m absolutely giddy over it. I began this journey in 1980.
I listen to music on Pandora at the recommendation of a college professor who told me that Pandora and its algorithmic music selection is the rage of his research assistants. Wanting to hang with the cool kids, I checked it out and was impressed. Now thanks to Darren Rowse at Problogger, I also listen to Sky.fm and enjoy the higher quality streaming but am not thrilled with the narrow selection of music choices. Thanks to my brother-in-law’s gift of XM Radio to Cathy I rarely listen to regular radio anymore.
