Digital communications is not as scary as it sounds. This post will show you what basic equipment is needed to get started. Once you get your digital communications running, help others in your network and consider starting a local digital net!
NOTE: A Ham License is required to TRANSMIT on digital modes
Benefits of digital communications:
Digital communications requires less power, transmits farther and is reliable even in poor conditions. Another benefit is, digital communication can only be ‘decoded’ by others set up for digital communications. It just sounds like a ‘humming or buzzing’ noise while transmitting to anyone monitoring the frequency without the digital equipment.
Digital communications does require a computer since it uses software such as fldigi. However, it does not require an internet connection for transmitting and receiving—it uses radio waves.
Here is a picture of an example of a basic digital comms setup:
List of components (pictured):
1) Computer (laptop, netbook, etc.) to run the free downloaded copy of fldigi
2) BaoFeng UV-5R Dual-Band Ham Radio
3) Signal Link USB for UV-5R (comes with cables and jumpers)
4) Plug & Play Jumper (recommended for easier set up instead of using jumpers)
NOTE: The Signal Link and Plug & Play linked above is for the BaoFeng UV-5R. Verify you are ordering the correct Signal Link and Jumper for your specific radio. TigerTronics has a customer service department if needed.
The purpose of the Signalink device is to act as an external sound card for your computer, making it compatible with other users’ computers. Once you have your gear, review the Signalink manual that came with your equipment to get your jumpers or Plug & Play installed.
To get started, you will need to download fldigi.
Configuring fldigi is quick and simple. Once you have it downloaded, follow the steps below:
1) Click on configure, then the operator tab and enter your FCC call sign. Click “save” and close.
2) Plug Signalink into the USB port and press red PWR button “on”.
3) Click “configure” tab and then select “sound card” from the drop down menu.
4) Select the USB options in the drop-down on both Capture and Playback. Save and close window.
5) Next, select the mode and you want to use in the fldigi program
(Refer to the Communications S.O.I. or the Scheduled Nets page for the operation mode and frequency)
6) Enter the call sign you want to call. You are almost ready to type and send your digital message:
Connect the cables from your Signalink to the radio and computer. Then, verify you have the correct frequency entered in your radio before you start transmitting and receiving messages.
To send a message:
Type your message in the blue box then click the purple TX button below the text. Once your message is sent, click the RX button to stop transmission
To receive a message:
If your equipment and configurations are set correctly, you will automatically receive messages in the upper text box. If the message is not legible, verify the SQL button in the lower right portion of the screen is checked yellow, and adjust the squelch bar next to the SQL button.
Additional resources:
TigerTronics SignaLink USB Interface Article (pdf)
Is there a way to use digital subtracting the middle piece just using the radio and computer?
Yes, you can use radio speaker and the laptop mic ‘in’, with just an audio jumper cable. You can also just hold the radio up to the external mic on the laptop. But that’s only for receiving. It’s always better though, if you use audio cables, as it helps eliminate ambient noises, making for better copy on the waterfall. For transmitting, you’ll need an external hand mic (lapel mic) to keep the radio as far away from the laptop as possible. If you transmit the radio right next to your laptop (especially over long periods/repeatedly), the RFI (Radio Frequency Interferrence) is known to actually cause damage to a computer.
Actually, a direct hookup between a laptop and an HT works well. No bulky interface. No hum or extra noise! Using audio patch cords between the computer’s speaker & mic jacks and the HT’s mic and speaker jacks and configuring the HT for VOX operation (for PTT) is all you need.
If your radio does not support VOX, some electronics can recreate the PTT. If your laptop is old enough to have a serial port, a resistor and opto-isolator will level-shift an RS-232 signal to PTT. For newer laptops, a few components (a few resistors, a diode, capacitor and transistor) can recreate the missing PTT signal. No need for isolation transformers etc. or a bulky interface. If you can’t do this on your own, find an Elmer. Since you’re a ham, you’ll be able to find a tech-savvy ham friend who can help you whip one up. COMMS UP!
73 & God bless
Yes, it ‘can’ be done. I’ve sent digital (PSK) from one laptop to another using only audio patch cables between the radio and laptop. HOWEVER, it often does not work and it is all dependent on the soundcard in each computer. Often times they aren’t compatible and the two laptops won’t talk to each other. The Signalink external soundcard takes care of this, and will eliminate much frustration. I can send digital back and forth with Joe, but not Jane. When we’re all using the same soundcard though (Signalink), we have comms between all of us. Soundcards aren’t standardized among all the computers out there. For receiving only, an audio patch cable from the audio ‘out’ of the radio to the microphone ‘in’ on the laptop is all that’s needed. Just remember to set the audio settings in the fldigi program by clicking the ‘configure’ tab, and then ‘sound card’ from the drop-down menu.
Some modern radios that have USB ports of them basically have a soundcard built in. You can use this soundcard for something like fldigi. An example is the icom ic-7100. See http://www.coilgun.info/hamradio/ic7100-fldigi.htm for an example. Granted this type of configuration is typically only found on newer (pricey) radios, but has time goes on and these radios lower in price in the used market it will be more affordable.
I use a ic-7100 with 1 usb cable going to computer with fldigi and it works great. Before then I would go the USB SignalLink option. It worked just fine, you just end up with a few more cables.
The only point I will mention is setting audio levels in any digital configuration is very important. Your acl meter should not be moving while you are transmitting. if it is you will be splattering and make a wide signal. Hopefully another article will be written explaining that.
Hello, am attempting to get an IC-7100 working with JS8Call now. Seems like I am _almost_ there… Have achieved the ability to get the frequencies noted by the radio’s screen and that noted in JS8Call GUI to replicate. Since the webpage you have linked to has been written, it seems the firmware in the IC-7100 has been updated and the menu items have changed. Have been trying this and that to no avail. Cannot seem to get the thing to transmit. Was wondering if you still have this setup working after updating firmware in the radio. Thank you, DZ-69
If, as the picture implies, you’re limited to communication between HTs or limited to 2m/70cm, then FM packet remains a viable option . The TinyTrak4 is a great KISS mode TNC with a good selection of HT cables, and Winlink RMS Express is a very easy to use client for point-to-point message exchange. Also – If real-time is not an option, then look into the Argent Data Systems SR-1 simplex repeater. It has the ability to receive and store up to 20 “audio” messages (including digital mode audio streams), and play them back upon entry of a DTMF password. An intriguing little device.
Howdy John Jacob
Do you know of the “Libertas Tablet” and whether or not it would work in this situation for digital comms?
I am contemplating purchasing one and this would be a big plus.
Thanks
PG310
I’m not familiar with it, or it’s operating platform. I do know that RMS Express (Winlink.org) is compatible ONLY with Windows. Stay away from Windows 10 whatever you do. Seriously.
Does anyone have the jumper wire setup for the Signalink if using the UV5R? A picture would be great. I obtained a UV5R and Signalink from a friend and it was set-up the same way it is for the Yaesu FT-897. I’m thinking that isn’t correct.
I cannot seem to find it online anywhere.
I don’t have the diagram for the wires. Tiger Tronics has great customer service and FAQ: http://www.tigertronics.com/
A computer is difficult for portability. What about a tablet that has longer battery and can charge via usb?
Yes. Several operators use them.