MSHV is an FT8/FT4/JT-mode application written by LZ2HV Christo. Its standout feature is multi-stream operation — running several FT8 QSOs simultaneously on different audio frequencies within the same band. That makes it popular for DXpeditions, contesters, and operators who want to maximize rate. This guide gets you from a fresh install to your first FT8 contact.
What you need
- A computer running Windows or Linux (MSHV has no official macOS build)
- An HF transceiver — multi-stream needs a radio with reasonable IMD performance if you plan to run more than one QSO at once
- A way to get audio between the computer and the radio
- A CAT cable so MSHV can control frequency and PTT
Step 1 — Download and install MSHV
Go to lz2hv.org/mshv and download the latest Windows or Linux build. Install with the default options.
MSHV can coexist with WSJT-X and JTDX — separate folders, separate config, no conflict.
Step 2 — Set your station info
- Open MSHV
- Go to Options → Settings (the menu structure varies slightly by MSHV version)
- On the Station page, enter your Callsign and Grid square
Step 3 — Configure your radio (CAT and PTT)
- Connect your radio to the computer via USB
- Make sure CAT is enabled in the radio’s menu and note the baud rate
- In MSHV Settings, find the Radio section
- Pick your Rig, the right Serial Port, and the matching Baud Rate
- Set PTT Method —
CATfor most modern radios, orRTS/DTRfor hardware PTT - Click Test and PTT to confirm the radio responds
Step 4 — Configure audio
- In Settings, find the Sound Cards section
- Input: pick your radio’s USB audio input
- Output: same device for output
- Set the sample rate to
48000 Hz(MSHV default) - Save and close Settings
Step 5 — Pick your mode of operation
MSHV has more operating modes than WSJT-X. Two that matter most for new users:
- Single decoder, single stream — behaves like WSJT-X. One QSO at a time. Start here
- Multi-answering CQ — when you’re calling CQ, MSHV can answer multiple callers in parallel on different audio frequencies. This is what makes MSHV unique. Read the documentation before enabling; it’s powerful but needs careful radio setup
For your first contacts, leave multi-stream off and operate single-stream.
Step 6 — Make your first FT8 contact
- Set the mode to FT8 in MSHV’s main window
- Tune your radio to 14.074 MHz USB
- Watch the waterfall — vertical streaks every 15 seconds means audio is flowing
- Decodes appear in the band activity panel
- Double-click any station calling
CQ - MSHV queues your reply
- Confirm TX Enable is on
- At the next 15-second window, your radio transmits
- MSHV advances the QSO and logs it at completion
Common gotchas
- Settings menus look different from this guide — MSHV’s UI evolves between versions and individual screens move around. The functional pieces (callsign, rig, audio, PTT) are always there, just sometimes under different submenus
- Multi-stream causes splatter or IMD complaints — multi-stream transmits multiple FT8 tones simultaneously, which puts more demand on your radio’s linearity. Lower your overall TX drive when running multi-stream; you may need to reduce stream count if your radio can’t handle it cleanly
- Test PTT fails — another program owns the COM port, or CAT is not enabled in the radio’s menu
- Computer clock drift — same FT8 requirement as WSJT-X and JTDX: within 1-2 seconds of UTC
When you want to operate hands-free
MSHV gives you the unique multi-stream capability, but the per-QSO loop still demands your attention — picking targets, managing filters, calling CQ, dismissing the Log QSO dialog.
That’s what we built Hamilton Auto FT8 for. It drives MSHV (and WSJT-X, and JTDX) over the standard UDP interface — picks callable stations from your filters, runs the sequence, auto-closes the Log QSO popup, optionally pushes QSOs to QRZ Logbook, and offers Hunter and Activator (POTA/SOTA) CQ modes. Single-stream operation is fully supported today; multi-stream coordination is on the roadmap.
Try it free: autoft8.com/downloads.
73 and good DX.