# Feld Hellschreiber

> Decode and transmit text via audio signals using the Hellschreiber system. (iPhone/iPad app by Black Cat Systems.)

- Source: https://appshunter.io/ios/app/feld-hellschreiber/id650758963 (this page in markdown: same URL + `.md`)
- Developer: [Black Cat Systems](https://appshunter.io/developer/301047032)
- Category: Utilities, Lifestyle
- Price: $2.99
- Rating: 2.80/5 from 5 App Store ratings · 16 written reviews indexed
- Age rating: 4+
- Requires: iOS 6.0 · 4 MB
- Languages: American English
- Released: 2013-05-28
- Data updated: 2026-08-23
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/feld-hellschreiber/id650758963/reviews.md

## What is Feld Hellschreiber?

Hellschreiber is a teleprinter system, developed in the 1920s, that transmits text via sound, much like an old facsimile (fax) system. Each pixel of a character is transmitted as a short burst of audio. It works even under very noisy and poor reception conditions, because your brain does the work of analyzing the received image to pick out the characters.

It was used by the German military during World War II to send messages encrypted by ENIGMA machines. Today it is used by amateur (ham) radio operators around the world to send messages to each other via shortwave radio. 

Feld Hellschreiber literally means "bright field recorder". Hellschreiber is sometimes referred to as simply Hell. 

Feld Hellschreiber lets you decode and transmit Feld Hell messages. Decoded text is continuously scrolled across the top of the display. You can type in text to transmit, or press a button to easily send canned text messages, such as CQ calls. Sound is picked up from your radio's speaker via the internal mic in your device, and transmitted audio comes out the speaker - you can also connect a patch cable to your radio's mic input via the headphone jack on your device to transmit the audio, if you wish. 

The slider control adjusts the display contrast, and the indicator to the right shows the volume. Adjust the slider for the best display. 

To transmit text, touch on the text entry field, and start typing. Each character will be sent when possible. When sent, it will be taken off the left end of this field, and displayed on the right end of the transmitted text field, to the left of the entry field, in a scrolling fashion. 

Canned text buttons are also available, touch one to send the text stored for that button. To edit a button, touch the Setup button, and then select the button you wish to edit. You can edit the name of the button, as well as the text. 

To decode transmissions, you just need to run the app, and set it near the radio's speaker or headphones, and watch the decoded text appear. It's that easy!

## Key features

- Decode Hellschreiber messages
- Transmit text messages
- Canned text message support
- Adjustable display contrast
- Real-time text scrolling
- Audio input/output via device mic/speaker

## Recent user reviews (10 of 16)

All indexed reviews: https://appshunter.io/ios/app/feld-hellschreiber/id650758963/reviews.md

### 5/5 — Only works on iPad not iphone

*2026-05-04*

Works great on iPad, but only receives on iPhone. Otherwise I’d have given it five stars

After significant trials, got working on iPhone.. Not problem with the app, just a setup problem on iPhone.

### 1/5 — Buggy interface

*2025-09-19*

Cannot be closed or swiped away without locking and unlocking the phone. Also always opens in landscape mode with no option for rotation.

### 3/5 — Too quiet

*2024-01-25, version 1.2*

The app doesn’t let you direct the sound to the speaker phone type output. It comes out just the ear piece and is very quiet. It seems you have to use an external speaker to make it louder.  The phone has a loud enough speaker in it already so I don’t know why they didn’t direct the sound out of the bottom speaker or make a way to control the output volume.

### 3/5 — Only works on iPad not iphone

*2023-03-21*

Works great on iPad, but only receives on iPhone. Otherwise I’d have given it five stars

### 4/5 — Rating of Hellschreiber

*2022-11-26, version 1.2*

I found this app excellent and performing perfectly as claimed on my iPad.. However, it performs inadequately on my iPhone. On the iPhone, it will not transmit. It receives fine. It just won’t emit any sound from the iPhone.

I’ve gone thru everything I could think of and reviewed every YouTube presentation on sound troubles with iPhone sound problems. Every other app I run on my iPhone emits sound properly.. only the Hellschreiber fails.

I contacted your help desk and he was very courteous and made many suggestions, but still no sound output. 

I was very discouraged and perplexed over this problem.

I would have rated the app five stars if the iPhone sound worked.  It’s great on the iPad.
Bearded Wizard

### 5/5 — Very Useful

*2021-10-22, version 1.2*

Great piece of kit.

### 5/5 — Perfekt

*2020-03-02*

Einzig was noch fehlt wäre die Möglichkeit das als Audio Datei zu speichern. 

Danke für die Mühe!

### 5/5 — Great!

*2019-08-25*

Use this nifty package with iPhone 6 and a homebrew cable going to my KX3 radio. Works very well as a super small digital field station. Easy to setup the macros for typical QSO. Highly recommend. de K5YR

### 5/5 — Does what it says

*2017-01-06*

Pretty good

### 5/5 — hellschreiber

*2016-07-16*

Works great on my iPhone 6+!

## Frequently asked questions about Feld Hellschreiber

### What is Feld Hellschreiber?

Feld Hellschreiber is a teleprinter system that transmits text by converting each pixel of a character into a short audio burst. It was historically used by the German military and is now popular among amateur radio operators.

### How does Feld Hellschreiber work?

The app decodes incoming audio signals from a radio, interpreting them as text characters. For transmission, it converts typed text into audio signals that can be sent over radio waves.

### Can I use Feld Hellschreiber offline?

The app's core functionality of decoding and transmitting text relies on audio input and output, which would typically require a connected radio. However, the app itself does not require an internet connection to operate once installed.

### What devices support Feld Hellschreiber?

Feld Hellschreiber is available for iPhone, iPad, and iPod devices. It is designed to run on iOS.

### How often is Feld Hellschreiber updated?

The latest version of Feld Hellschreiber is 1.2, which was released on May 8, 2017. Updates are not frequent, with the last update being several years ago.

### What is the age rating for Feld Hellschreiber?

Feld Hellschreiber has an age rating of 4+, indicating it is suitable for users aged 4 and older. This rating is based on general content appropriateness.

### Does Feld Hellschreiber have ads?

No, Feld Hellschreiber does not contain advertisements. It is a paid application that offers an ad-free experience.

### What do users think of Feld Hellschreiber?

User feedback for Feld Hellschreiber is limited, with an average rating of 2.8 stars from 4 ratings. This suggests a mixed reception among its current user base.

## Version history (last 4 releases)

### 1.2 — 2017-05-08

This app has been updated by Apple to display the Apple Watch app icon.

Updates for iOS 10.3

### 1.1 — 2014-09-24

Bug fixes for iOS 8.

### 1.0.1 — 2013-09-11

Corrected several bugs that could cause a crash.

### 1.0.0 — 2013-05-28

No release notes.

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## More apps by Black Cat Systems

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All apps by Black Cat Systems: https://appshunter.io/developer/301047032

## Related topics

[feld hellschreiber](https://appshunter.io/ios/topics/feld-hellschreiber)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-23.*