There are many SDR radios that can be used as panadapters with any main radio supported by N4PY. As long as they can be controlled either by HDSDR or some version of PowerSDR, they can be used.
In the N4PY scheme, normally no IF from the main radio is used at all. Instead, the SDR panadapter radio is run in parallel with the main radio, normally sharing the same antenna. Sharing the antenna can be a little tricky depending on the main radio used. If the main radio has an RX OUT connection, then all you do is connect the main radio RX OUT connection to the SDR panadapter radio's antenna input. Radios that I know have an RX OUT are the Icom 7800 series, 7600, Yaesu FTDX 3000, 5000, 9000. Also, I have specific easy mods for the Omni VII, Orion, Pegasus, and Jupiter to add a RX OUT antenna connection.
If your radio does not have an RX OUT connection, there are 3 solutions. 1) Just run a second separate wire antenna to the SDR panadapter radio.
OR
2) Add a DXEngineering device described near the bottom of this page.
OR
3) Add an MFJ 1708 described near the bottom of this page.
Using any HDSDR Radio with your Radio as a Panadapter
The External Ports settings window (referred to as the THP port) is where you select a comport to connect your radio to a panadapter. Any panadapter radio that can be controlled with HDSDR can be used a panadapter and sub-receiver. The setup requires several steps.
They are as follows:
1) Install VSP Manager. I have a link on my "Previous Versions" page for it.
2) Use VSP Manager to define a comport pair. Let's assume you define COM10 and COM20. They can be anything as long as they are not used by anything else.
3) Install HDSDR and the panadapter radios drivers.
In HDSDR, in F7 Options, select "CAT to HDSDR". Set the PORT to one of the comport pairs (like COM10 in this example). Select "Activate". Make sure it shows a check mark. The baud rate does not matter with a virtual comport.
4) In "User5 TransV", configure the N4PY Pegasus program's Tokyo HP comport for the other half of the virtual comport pair (like COM20 in this example) for the Tokyo HP comport. Also turn on the check box "Tokyo HP Comport", "Use THP Comport for EXT Logging Program". If you are using an antenna connection to the SDR radio, turn on "SDR-IQ/HDSDR Pan". If you are using a a fixed IF output to the SDR radio, turn on "HDSDR Fixed IF". After these changes are made, exit and restart the program.
The THP comport will now communicate directly with HDSDR. This will allow the HDSDR radio panadaptor to work very nicely with your radio.
Using any Flex Radio with your Radio as a Panadapter
The External Ports settings window can be used with your radio and Flex Radio's Flex 1500 (or any other Flex radio) as a panadapter and sub-receiver. To use the Flex-1500 as a panadapter, several steps must be done. This setup is built around the current version PowerSDR version from Flex Radio. Please note all panadapters are muted unless Dual receive is turned on from the main radio screen.
They are as follows:
1) Install VSP Manager. I have a link on my "Previous Versions" page for it.
2) Use VSP Manager to define these comport pairs. Let's assume you define COM10 and COM20. They can be anything as long as they are not used by anything else.
3) Install the Flex radio with all its supporting software.
Configure PowerSDR for CAT using one of the comport pairs (like COM10 in this example). In PowerSDR, turn on "Allow Kenwood AI Command". When running with PowerSDR, changing the mode or filter from the PowerSDR program does not change anything in the N4PY program. Mode changes in the N4PY program are sent to PowerSDR. Filter values are not sent to PowerSDR.
4) Configure the N4PY Pegasus program's Tokyo HP comport for the other virtual comport (like COM20 in this example) in the USR5 settings window for the Tokyo HP comport. Also turn on the check box "Tokyo HP Comport", "Use THP Comport for EXT Logging Program". Also turn on "PowerSDR Panadapter". After these changes are made, exit and restart the program.
The THP comport will now communicate directly with powerSDR . This will allow the Flex radio panadapter to work very nicely with your radio.
DXE-RTR-1A Solution to Share Antennas
The DXE-RTR-1A can be used to share antennas between the transceiver and the SDR receiver. This is a $170 unit that will provide a safe way to share antennas between the SDR receiver and transceiver.
Setup
1) Place the "Main On" switch in the middle "RX ANT" position. 2) Connect the amp key line of the transceiver to the "Transmit Ground" connection. 3) Connect a radio shack Y cable (part #42-2535) between the "Main ANT OUT" and "RX ANT IN" connections. 4) Connect the third leg of the Y cable to the antenna input of the SDR receiver.
MFJ-1708 for an Antenna Sharing Solution
One solution to share antennas is to add an MFJ-1708 T/R switch. This unit will automatically sense RF from the transmitter and then remove the panadapter radio from the receive antenna connection. But the MFJ switch will also remove the transceiver from the transmit connection while in receive. So the MFJ switch needs two very simple mods. You must solder a 14 gauge wire between the transmit and antenna SO-239 connections. This will then make the switch operate properly for this use. Additionally, you should wire the relay to energize from your radio's amp key line for faster and safer switching.
Also for safety in case something fails I recommend adding two back to back diodes between the receive SO-239 and ground. These diodes will act as limiter and further protect the panadapter receiver in the event of a timing problem. Radio Shack 276-1661 diodes should be fine.