Tim Havens is an avid CW operator on the ham bands and primarily uses his Yaesu FTDX-5000 transceiver for this purpose. At the same time he also uses a software defined radio coupled with an upconverter as a panadapter by connecting the SDR to the 9 MHz IF output of the Yaesu.
To get around this Tim decided to use the Airspy in a special configuration. First he used the external clock input of the Airspy to connect to his Jackson Labs “Fury” GPSDO. This device uses GPS satellites to generate a very accurate 10 MHz clock, with almost zero drift. Secondly, to get around the need for an upconverter with it’s own frequency drift he used the ADC1 direct sampling input ports on the Airspy to connect to the 9MHz IF output of his FTDX-5000 through an extra band pass filter and LNA.
Tim writes that he will soon update his post with more images and a video.
The Drake 2B is an old analogue tube based radio from 1961. Although it is so old it is still considered a decent shortwave receiver. Over on YouTube user M0HBR decided to bring his Drake into the modern age by coupling it with a panadapter made from an RTL-SDR dongle. A panadapter is a device that allows you to view the RF spectrum and waterfall of a normal radio.
To do this he tapped into the 455 kHz IF output of the Drake and amplified it with a homebrew FET source-follower, before connecting it to the RTL-SDR. He then uses the HDSDR software to listen to and display the received signals on the waterfall.
Over on YouTube user Jay Moore has uploaded a video explaining how to connect an RTL-SDR dongle to the IF stage of a hardware radio in order to create a panadapter. In the video Jay briefly explains how a radio with an IF stage works and then shows how he tapped into his Sansui 2000 hardware radio’s IF stage directly from the circuit board. The IF stage then connects to a ham-it-up upconverter which connects to the RTL-SDR.
By connecting the IF stage of a hardware radio to the RTL-SDR it is possible to use the hardware radio as the receiver while using the RTL-SDR to still maintain the benefits of a spectrum display. Most purpose built hardware radios will have better reception than the RTL-SDR.
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.
For people already with expensive ham radios, the RTL-SDR can be used as a cheap panadapter. A panadapter is device that allows you to visually see the RF spectrum and waterfall being received by the ham radio. There are multiple (expensive) commercial panadapters available, but combined with a PC or laptop, the RTL-SDR will work just as well.
In this video YouTube user akdude47 shows a tutorial on setting up the RTL-SDR as a panadapter for a Yaesu FT-857. The setup involves connecting the IF output of the radio to the RTL-SDR, and putting in some settings into HDSDR.
How to setup a RTL SDR with HDSDR and a FT-857 for a panadapter and second receiver.