Tag Archives: SDR

Featured, General, Newsletter, Station Equipment, Youth Activities

PTT Switch for Remote Operation

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When the Nashua Area Radio Society’s Student/Teacher Contest Series was first set up, Fred and Anita (AB1OC/AB1QB)  offered up their station to my son Keith (KC1IMK) and other students that do not have a station at home. Fred and Anita have an amazing station at their QTH and you can find more information on it here.

Then COVID arrived and sharing mikes, headphones, and keyboards at other people’s houses are no longer acceptable.  We cannot risk getting each other sick.  Another way is necessary.  Remote Operation is here!

Fred (AB1OC) and Jamey (AC1DC) worked out the kinks for setting up Remote Operation first.  Then Fred invited Keith and me to try it out. After a couple of hours online with Fred to set up, we were on our own.  Contest Calendar showed the Helvetia Contest that night so we pointed the beams toward Switzerland and called CQ.  Several stations pounced on Keith at once. He worked hard with the mouse, bouncing from the radio PTT button to logging in N1MM.  Once the pile-up was cleared, he pulled off his headset and said “I really wish I had a footswitch like Field Day“.

Remote PTT Switch for SmartSDR

Driven to maintain my “Super-Dad” status, I went to work.  I found a few references at the FlexRadio site:

https://community.flexradio.com/flexradio/topics/physical-ptt-for-remote-smartsdr

https://community.flexradio.com/flexradio/topics/remote-footswitch-how-to-lan-vpn-solution

Looked pretty straight forward to build a Remote PTT Switch.  Configure a SmartSDR CAT interface to monitor hardware flow control pins in a standard serial port. The hard part today is to find a serial port.  They have all been replaced by USB.

There are lots of USB to Serial adapter cables available today for around $20 that should work well. I would recommend one based on the FTDI chip.  Jamie (AC1DC) successfully used a Sabrent USB 2.0 to serial from Amazon:  https://www.amazon.com/gp/product/B07RFNHTL9/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

I dug out a 15-year-old Belkin adapter from the back of my shack and installed it.  A new Com3 port showed up in Windows 10 device manager.

USB to Serial Adapter for Remote PPT Switch
USB to Serial Adapter

SmartSDR CAT will detect if RTS is shorted to CTS in a Com port.

SerialPinOut

This is a very standardized interface and it was easy to find the pin definition.

Pin 7 is RTS

Pin 8 is CTS.

Easy to spot as they are the center two pins of the row of four.

I also had the mating 9 pin D connector in my bin of parts.  One could probably solder to the pins of the adapter, but I would recommend a connector.  I cut off the 1/4″ plug from a footswitch I bought from Amazon. The two leads were soldered to pins 7 & 8.

https://www.amazon.com/Philmore-LKG-Momentary-Foot-Switch/dp/B004GIIYK0/ref=sr_1_7?dchild=1&keywords=30-17090&qid=1587913482&sr=8-7

Footswitch for Remote PPT Switch

To test it, I downloaded ComTestSerial from Microridge  https://www.microridge.com The test software confirmed the hardware worked.  Each time I pressed and released the footswitch the CTS light in the top right corner changed between Red and Green.

Configuring FlexRadio SmartSDR

Now to configure the software. Open SmartSDR CAT and add a port.  Give it a name.  Set Port Protocol to PTT,  set Port type to Serial, set Serial Port to Existing, and set CAT COM to your new Com port.  Mine was Com3.  Set VFO slice A. Select RTS. Hit save.

SmartSDR Setup for Remote PPT Switch
CAT settings

I found some open spectrum on 20m, crossed fingers, and pressed the switch.

Voila!  It transmitted!

With prolonged use, I found my old adapter was not up to the job.  The drivers were not meant for Windows 10.  It missed about 1 out of 10 switch presses.  I have since upgraded and the new Remote PTT Switch works great.

73, Mark/KC1IML

And here is a link to a more current USB to serial adapter for use in this application. You can learn more about the remote operating setup at AB1OC-AB1QB here.

Fred, AB1OC

Featured, General, Newsletter, Station Equipment

Remote Operation

While isolated in our homes I am finding amateur radio a very therapeutic distraction from all the chaos in the world. I look forward to Contest Weekends and like a lot of you, I am looking for new projects and adventures in amateur radio. One recently came my way – Remote Operation over the Internet.

Last weekend I got the opportunity to set up my computer to work Fred and Anita’s (AB1OC/AB1QB) station remotely. Fred and Anita have an amazing station at their QTH and you can find more information on it here. Of course, I was game to test Remote Operation out! Fred and Anita would like to open their station up remotely for the Nashua Area Radio Society’s Student/Teacher Contest Series as some of the Youth and Teachers in the contest do not have access to a station at their homes and of course, no one is getting together in groups right now.

Software and Networking

The first thing we had to do was to load the software on my computer and make sure we could communicate properly. Luckily, last week Connor (KC1GGX) and I ran CAT 5e cable from our router through the ceiling in the basement to the computer in our shack. See what I mean about looking for projects! This gave us a good internet connection to work with.

We used the program SmartSDR for Windows to control Fred’s station. The download is pretty straight forward and Fred handled the process of connecting my computer to his station via the web. The SmartSDR has three modules. SmartSDR is the panadapter and “virtual” control face of the transceiver, SmartCAT which controls the interface between your logger and the radio and SmartDAX which is for controlling digital operations.

Remote Operation

Once Fred got it all configured and talking to my logging software – I am using DX Lab Suite – it was time to test it out and see what it could do.

Operating Using An SDR

The signals were very clear and strong and using an SDR really gives you great control of being able to adjust your filters and bandwidth. I was able to move frequencies, change bands, and pretty much anything else I would have been able to do from the AB1OC/AB1QB shack… except rotating the antennas.  We didn’t quite use the “arm-strong” method (moving and antenna manually as we’ve done for Winter Field Day on our VHF antennas), but I would call Fred on the phone and ask to have the antennas pointed in another direction.

Remote Operation

Remote Operation

Pointing Rotating Antennas

A couple of days later, Fred found a solution for rotating the antennas as well with a program called PstRotatorAz.  This gives complete control of moving the antennas while working remotely.

Remote Operation

Abby, AB1BY, and I operated from AB1OC/AB1QB’s station remotely over the weekend and had a great time. The only drawback we found is when switching between the SDR window and the logging window you would lose the ability to use the space bar as your PTT, which meant a lot of moving the mouse around and clicking.

Getting Ready To Contest

Mark, KC1IML, and Keith, KC1IMK have also set up their station to work remotely with Fred and Anita’s station and have come up with a solution to the PTT problem as well. They used an old USB to serial adapter and soldered the leads from a footswitch to a few pins on the serial adapter and they have the footswitch working.

This has been a lot of fun to try out and big thanks out to Fred for putting in all the time to get Remote Operation up and working!

Jamey, AC1DC

Featured, General, Newsletter, Space, Station Equipment

Adding L-Band (24 cm) to Our Satellite SDR System

We’ve recently received our L24TX Transmit Converter from Down East Microwave. The unit is compact, simple, and produces up to 25W output in the satellite section of the 23 cm band (1260 MHz – 1270 MHz, actually 24 cm). The L24TX is a transmit-only device that is intended to enable L-band uplinks for Satellite use. This article is about our most recent project which involved integrating the L24TX into our Flex Satellite SDR System to enable L-Band Satellite operation  …

Source: Satellite Station 4.0 Part 10 – Adding 23 cm To Our Satellite SDR

We are making progress on our project to enable remote Satellite operation via the Internet. The latest step is the addition of L-band (24 cm) uplink support to our Flex Satellite SDR System.

L-Band Satellite SDR
L-Band 24 cm Transmit Converter

We’ve also made some good progress on custom software to link MacDoppler and our Flex Radio Satellite System via the Internet.

The article in the link above shares information about how to go about adding Transverters and Band Transmit Converters to a Flex SDR. the step needed to configure the Flex SmartSDR software, as well as links, cover other aspects for our Satellite System 4.0 Project are included.

You can read the latest updates about this project via the link above.

Fred, AB1OC

Radio Amateurs Developing Skills Worldwide