Category: HF

Receiving Weather RTTY and FAX with the RTL-SDR

YouTube user Tiago Sousa shows how he was able to receive weather Radioteletype (RTTY) data using the RTL-SDR, an upconverter and MultiPSK. Weather RTTY is broadcast by weather services such as the Deutscher Wetterdienst (DWD) which is broadcast from Hamburg, Germany. It is intended for people at sea.

Tiago used an RTL-SDR with upconverter and an 11 meter long wire antenna. For the software he used SDR# and piped the audio to MultiPSK.

Weather RTTY - DWD Hamburg heard in Portugal

Tiago has also uploaded a second video showing him receiving Weatherfax with the same setup. Weatherfax is a signal that transmits a fax image showing weather patterns.

Weather Fax - DWD Hamburg heard in Portugal

Building an Upconverter from the LNA4HF

Adam the manufacturer of the LNA4HF has recently uploaded a video showing how to easily build an upconverter from the LNA4HF. The LNA4HF is a low noise amplifier intended for use with SDRs like the RTL-SDR. The video shows how to connect up two components, the Mixer and Oscillator which are required to create the upconverter.

HF upconverter built from the LNA4HF

Using the RTL-SDR as a Panadapter

PW2VLW’s shows on his blog how to adapt an Icom IC-706 hardware radio to be able to use an RTL-SDR as a cheap panadapter (Note site is in Portuguese, so use Google Translate). A panadapter is device that allows you to visually see the RF spectrum and waterfall being received by the ham radio.

He shows instructions on how to perform the required modification to get the IF output of the ICOM, and also shows how to interface the PC with the ICOM so that it may be controlled directly via HDSDR.

Panadapter
Panadapter

RTL-SDR + Upconverter vs. Portable Shortwave Receiver

Akos from the SDR for Mariners blog has put together an article doing a comparison between the RTL-SDR + ham-it-up upconverter and a Grunding G8 Traveler II Digital conventional portable hardware shortwave radio.

His results show that the RTL-SDR and portable receiver are comparable in terms of performance, with a slight edge to the RTL-SDR. He adds that software tweaks available in SDR# can improve the voice quality for the RTL-SDR. However his final recommendation for general shortwave listening is that the portable is still the better option due to it’s ease of use.

RTL-SDR + Upconverter vs. Portable Shortwave Radio
RTL-SDR + Upconverter vs. Portable Shortwave Radio

KN0CK and KF7LZE Custom HF RTL-SDR Receiver Revision 5

Update: KN0CKs products are now available at http://www.kn0ck.com/HF_SDR/.

Previously on this blog we’ve seen KN0CK release his custom modified RTL-SDR tuners which have built in upconverters for accessing the HF bands. Revision 5 of the KN0CK receiver is now almost ready for sale, and will be sold over at KF7LZE’s webstore Easy-Kits.com.

Revision 5 promises to be lower priced as it will run using the direct sampling mod instead of using an upconverter which would require more components. It will also use a Mini-Circuits MAR 8 wideband amplifier to improve weak signal performance.

Kn0CK and KF7LZE RTL-SDR HF Receiver Rev. 5
Kn0CK and KF7LZE RTL-SDR HF Receiver Rev. 5

Upconverter Comparison: Nooelec Ham it Up vs SDR Up 100

A few weeks ago Akos from the SDR for Mariners blog did a review of the SDR Up 100 Upconverter, and he promised to compare it with the Nooelec Ham-it-up Upconverter when it arrived. He has now done the comparison, and written about it on his blog.

For each test he used a gain of 0dB and the same 20 foot random wire antenna. Interestingly, his results show that the SDR Up 100 significantly outperforms the Ham-it-up upconverter. We believe that this may be as the SDR Up 100 has an LNA built into it whereas the Ham it up does not.

Update: Akos has now included comparisons with various RTL gain settings.

upconverterCompare
SDR Up 100 vs Ham It Up
Nooelec vs Up 100 comparison
Comparison Images

Review of the SDR UP-100 Upconverter

Akos from the SDR for mariners blog has written a review on the SDR UP-100 upconverter. The SDR UP-100 is a 50 USD upconverter for the RTL-SDR and similar software defined radios which is made by the same person behind the LNA4ALL low noise amplifier. Upconverters allow the RTL-SDR to receive between 0 and 30 MHz, where ham radio, military, marine and many other interesting signals exist.

In the review Akos tests the SDR UP-100 with a 6 meter random wire antenna and an RTL-SDR. His results show that the upconverter works well as expected. In the future he hopes to compare the SDR UP-100 with the Ham-It-Up Upconverter from Nooelec.

SDR UP-100

Version 5.0 of the CT1FFU Upconverter Now Available

Version 5 of the popular CT1FFU HF upconverter which is often used with the RTL-SDR and Funcube software defined radios has been made available for sale. A ready built and tested version 5 CT1FFU upconverter will cost you 55 Euros. See the circuit diagram and technical specs in this pdf file.

The upgrades include

– Smaller size PCB

– 4 new holes for screwing PCB

– MiniUSB connector

– 2 led 5V indication USB/ Phantom Power

– It runs with phantom power directly from Fun Cube Dongle’s SMA cable

– USB power for generic RTL TV dongle sticks

– Separeted antenna inputs HF/6m and VHF/UHF

– Automatic internal relay antenna switch: HF or Bypass VHF and UP

– WFM broadcast filter avoiding saturation of SDR front-end

– LED indication for converter running

– DBM diode ring mixer 7 dBm: This ensures exellent HF reception performance

– LO on 106.250 Mhz or 65.520Mhz: This avoids interference from WFM radios

– Tests made by hams worldwide reveal exceptional clean reception on HF

– Technical assistance after selling

– Either ready built and tested or as KIT easy to build by yourself

– Worldwide shipping and tracking is included in advertised price

– You can now choose the LO freq: 106.250Mhz or 65.520Mhz models