Feld-Hell Digital Mode

Feld-Hell Digital Mode on FeldHellClub@groups.io

What is Hellschreiber? Hellschreiber, or Hell, is a method of sending and receiving text using facsimile technology.  It is unique in that the characters are not decoded, but “painted” or printed on a screen.  There are several modes of Hellschreiber, the most popular being a single-tone version call Feld-Hell, an on-off keyed system with 122.5 dots/second, or about a 35 WPM text rate.  FH has a narrow bandwidth of about 75 Hz.  Feld-Hell also has the advantage of having a low duty cycle meaning your transmitter will run much cooler with this mode.  

  • For a terrific explanation of Hellschreiber, we highly recommend the ZL1BPU web site, which explains everything you need to know about this mode, including the most pressing question, “why does Hell transmit two lines of text?
  • There is also a great introductory video on You Tube by Randy, K7AGE which you can see here

Feld Hell Frequencies

(from the FHC website…)


 Band Frequency
 160 Meters 1.843-1.844 MHz
 80 Meters 3.578-3.584 Mhz
 40 Meters 7.080-7.086 MHz
 30 Meters 10.137 10.134 Mhz (Region 1)
 20 Meters 14.063 MHz-Preferrred
 14.073* MHz-See Note
 17 Meters 18.105 MHz
 15 Meters 21.063 Mhz
 12 Meters 24.924 MHz
 10 Meters 28.063
 6 Meters 50.286 MHz

Note: For 20 meter ops, the FHC calling frequency is 14.063 and UP to 14.069. PSK31 ops are on 14.070 and the QRP club uses 14.060 as their calling frequency. We do not wish to cause interference to each other. A reminder, QRP is a power reference, not a mode. If using 14.073, be sure to avoid interference with the JT65 or FT8 area. Even though some may encroach on our segment, we need to be be the good guys!

Hellschrieber / FHC Net

The Hellschreiber/Feld Hell Club Net will be held in FSK HELL-105 mode Thursday evening in North America with early check-ins beginning at 8:45 PM EDT (Friday morning at 0045 UTC day & time).

  Net start time in North America:

Thursday at 9 PM EDT (Friday morning at 0100 UTC day & time)

7089.50 kHz (center) = (7088 kHz dial + 1500 Hz waterfall).

Mode: FSK HELL-105 (Aka FMHELL)

Join up with us on the Feld HellClub Group

Feld Hell Club website

Feld Hell Community Facebook Page

Feld HellClub @ Groups.io

Feld Hell Club Membership Roster

Monthly Hellschrieber Sprints

2020 Sprint Schedules

Hellschrieber Sprint Rules


Olivia Digital Mode Radioteletype on HF Olivia@groups.io

NOTE: This info is provided by NW7US and the Olivia Digital Mode on HF Radio (Contestia included) group on Facebook and on Groups.io (via http://OliviaDigitalMode.org). It is provided as Educational purposes only.

About the Olivia MFSK Digital Mode


Olivia MFSK is an amateur radioteletype protocol designed to work in difficult (low signal-to-noise ratio plus multipath) propagation conditions on shortwave radio (i.e., high-frequency, or HF) bands. The typical Olivia signal is decoded when the amplitude of the noise is over ten times that of the digital signal! It is commonly used by amateur radio operators to reliably transmit ASCII characters over noisy channels (slices of high-frequency–3 to 30 MHz, HF–spectrum) exhibiting significant fading and propagation phasing.

The Olivia digital modes are commonly referred to by the number of tones and the bandwidth, in Hertz, used. Therefore, it is common to express the Olivia digital mode as Olivia X/Y (or, alternatively, Olivia Y/X ), where X refers to the number of different audio tones transmitted and Y refers to the bandwidth in hertz over which these signals are spread. Examples of common Olivia modes are 8/250 (meaning, 8 tones/250-Hertz bandwidth), 16/500, and, 32/1000.


The protocol was developed at the end of 2003 by Pawel Jalocha. The first on-the-air tests were performed by two radio amateurs, Fred OH/DK4ZC and Les VK2DSG, on the Europe-Australia propagation path in the 20-meter shortwave radio amateur band. The tests proved that the Olivia protocol (or, digital mode) works well and can allow regular intercontinental radio contacts with as little as one-watt RF power (when propagation is highly-favorable). Since 2005, Olivia has become a standard for digital data transfer under white noise, fading and multipath, flutter (polar path) and auroral conditions.

Current Community

Our community is strong, and growing in number. We have participants in many countries. To foster the community’s growth and education, we must connect with each other.

The Facebook group is dedicated to instant communication for spotting, scheduling, and so on. Please join both of these groups.

Please share this everywhere possible, as part of our effort to rekindle the love for our conversational mode, Olivia.

Voluntary Channelization

Since Olivia signals can be decoded even when received signals are extremely weak, (i.e., signal to noise ratio of -14db), signals that are strong enough to be decoded are sometimes below the noise floor–below our ability to hear them, and not visible on the waterfall display–and therefore impossible to search for manually (by listening for the tones, or looking on the waterfall).

Therefore, in order to find other Olivia digital-mode signals, amateur radio operators have voluntarily decided to use channelization for this mode–at least for initial contact. This channelization allows even imperceptibly weak signals to be tuned properly for successful reception and decoding. Once contact is made, the operators are encouraged to move off of the calling frequency so that the channel may be used for other amateurs also trying to make that initial connection with other weak-signal stations.

By common convention, amateur stations initiate contacts on Olivia by utilizing the 8-tone, 250-Hz bandwidth configuration and then switch to other configurations (often, 8/500 when conditions are favorable) to continue the conversation. Below, you will find the lists of the common center frequencies of the weak-signal calling frequencies used in the amateur HF radio bands.

Current Olivia Calling Frequencies on HF

As stated, above, it is often best to get on standard calling frequencies with this mode because you can miss a lot of weak signals if you don’t.

Note: some websites publish frequencies that are right on top of weak-signal JT65 and JT9 segments, and now, FT8/FT4 signals. DO NOT QRM (interfere with) weak-signal QSOs! You might not see or hear them, but those modes are often, if not always, occupying the neighboring frequencies right above our calling frequencies.

We (the active Olivia community members) suggest using Olivia 8/250 as the starting configuration when calling CQ on the USB frequencies that we’ve designated as our Calling Frequencies. As you’ve deduced by now, a calling frequency is a center frequency on which you initially call, “CQ, CQ ,CQ …” and then, once communications are established with an answering station, and with the agreement with the answering operator, you both move your operation to a new nearby clear frequency, perhaps changing the number of tones and changing the bandwidth, at your mutual agreement and discretion. Even though 8/250 is slow, the CQ call is short. But, it is narrow, to allow room for other QSOs nearby.

Our Current (2019) Suggested Olivia Calling (and Listening) Frequencies

The frequencies listed below are suggested frequencies on which can be found WEAK (i.e., a signal that you cannot hear, a signal not seen on the waterfall) Olivia signals. While it is easy to spot a STRONG Olivia signal anywhere on the waterfall, by using these suggested calling frequencies at least once and a while, you will enable us to find your signal when the signal is too weak to hear and too faint to see on the waterfall. Olivia can do well with weak signals. Yes, our suggested 8 tone with 250 Hz bandwidth results in slow transmissions. But, it is one of the better settings when attempting to decode very weak signals. Once you make contact, you can move up or down a bit, away from the calling frequency, and then change to 16/500 or 8/500 to make the conversation go faster. But, on a calling frequency, it is advisable to configure operations in such a way as to increase the likelihood that you will find and decode that weak signal.

In the following list, CENTER is where you place the center of the software’s cursor, and click to select that center frequency on the waterfall. If you use the DIAL frequency from this list, then click 1500 Hz offset up the waterfall (1500 Hz to the RIGHT of the LEFT side of the waterfall, if your waterfall is oriented horizontally with the lowest frequency on the left). This results in the software and transceiver being correctly tuned for the CENTER frequency.

The listing shows CENTER, then DIAL, then the number of tones and the bandwidth.

CENTER – DIAL (Tones/Bandwidth)

and, so on…


Suggested Calling Frequencies (Weak Signal)

Reference Listing:

Suggested Calling Frequencies (Weak Signal)

Example (screen grab showing an example):

ALSO: If your software is able to decode/encode the Reed-Solomon Identification signals (RSID), please turn on both received and transmit RSID.


Do not switch to other modes without calling CQ for at least a five-minute window. It is horrid when people call CQ and change settings, modes, bandwidths, tones, every time they call CQ! Allow people time to get their software set to the right configuration, and ready to answer your CQ call.


Make sure that your signal does not cross into other sub-bands where weak-signal modes are active. For instance, do not have any part of your signal at 14073.5 kHz or higher, as this is the sub-band for FT8, JT65A, JT9. DO NOT QRM (interfere with) WEAK-SIGNAL MODES such as WSPR, JT65A, and JT9! BE AWARE OF THE BAND PLANS OF THOSE MODES!

Operating OLIVIA

1. Please make sure you are using the RSID (Reed Solomon Identification – RSID or TXID, RXID) option in your software. RSID transmits a short burst at the start of your transmission which identifies the mode you are using.

When RSID does that, those amateur radio operators also using RSID while listening will be alerted by their software that you are transmitting in the specific mode (Olivia, hopefully), the settings (like 8/250), and where on the waterfall your transmission is located. This might be a popup window and/or text on the receive text panel. When the receiving operator clicks on that link or popup button, the software moves the waterfall cursor right on top of the signal identified by the RSID and changes the mode in the software. This will help you make more contacts!

NOTE: MixW doesn’t have RSID features. Request it!

2. Olivia is NOT a weak-signal mode.  While it is a mode that can decode weak signals, it is not a weak-signal mode like JT65 or FT8. The Olivia mode was designed not for weak-signal decoding as the primary design objective, but to overcome propagation-path phase issues and transpolar-region propagation challenges on HF.

There are no points won by barely making a contact. In USA FCC regulations, you use the power necessary to make the QSO. Typically, with poor propagation, 100w or more is the minimum to establish a reliable circuit. However, BEWARE! You cannot set your radio’s output power above that which your radio’s manufacturer has established as safe for full-duty cycle operation! You also must be sure that you do not overdrive the audio chain into your radio. Also, be sure that you do not have RF coming back into your audio chain. Let’s say this, again: Yes, 100 watts is acceptable, and sometimes completely needed to make the QSO reliable. Don’t let anyone convince you otherwise.


Common Windows of Olivia Operation on HF

(this is still a work-in-progress; your input is welcome)

+ 160m: 1835 kHz – 1837.9 kHz
+ 80m: 3571 kHz – 3573.9 kHz
+ 40m: 7071 kHz – 7073.9 kHz (500, 250, or 125 Hz configurations mostly)
+ 30m: 10141 kHz – 10144 kHz (500, 250, or 125 Hz configurations mostly)
+ 20m: 14071 kHz – 14073.9 kHz (500, 250, or 125 Hz configurations mostly)
14104.5 kHz – 141079 kHz (1000 or 2000 Hz wide configurations mostly)
+ 17m: 18102.65 kHz
+ 15, 12, 10 and 6m: Usually 500 Hz above PSK activity – 21071.4 kHz, 24921.4 kHz, 28121.4 kHz
+ 50.291 MHz ???

Illinois ARES Wellness Net

During the Covid-19 Pandemic, we are running an ARES Wellness Net

Daily – 12:00 PM CDT (1700 UTC)

More info about this net is available at:

Illinois ARES website

View the Daily IL-ARES Wellness Net Report (updated 6:00PM CDT daily)

 IL-ARES Wellness Net Check-in Summary Report

IL-ARES Wellness Net Preamble

Illinois ARES Counties-Check-in Worksheet

View my IL-ARES Shared Documents folder

We Run several Netlogger Sessions during our Wellness Nets

Daily – 12:00 PM CDT (1700 UTC)

Be sure to Monitor the correct session Name listed for the Mode / Band you are checking into.

Netlogger Session Names….

 HF-Illinois ARES Wellness Net (3.905 Mhz-80 meters)

  60m-Illinois ARES Wellness Net (5.3715-dial / 5.3730-center; 60 meters channel 4 USB)

  Digital Voice-IL-ARES Wellness Net (Illinois Link-DMR, P25, NXDN, Fusion, Dstar)

  Rptr-IL ARES Wellness Net (Okaw Valley ARC Linked Repeater System)

  Echolink-IL ARES Wellness Net (Echolink Node WB0VTM-L 824404)

IMPORTANT: (Loggers) – Download the Netlogger Master Club Profile before logging your net sessions:


(Win10: place in C: \users\your_profile_folder\Appdata\Roaming\Netlogger\MiscProfiles)

(Linux: place in ~/.config/Netlogger/MiscProfiles