RFSM2400 and WinLink Winmor

Today I did some tests focused on the file transfer speed using two soundcard modems.

RFSM-2400 receiving test

RFSM-2400 is a freeware client program which can transfer files  over a radio channel, using MIL-STD-188-110A standard (300Hz to 3.3 kHz-2400 baud).

Winmor TNC, is a donationware program with a modulation scheme that resembles very close with the one used on PACTOR modems. The speed is bandwith related and is adaptive between 200 Hz and 2000 Hz.

RFSM 2400 can't be used to send files to internet servers but the Winmor is widely used with RMS Express to connect to various iGates around the world to send e-mails.

For tests I used a FT-991 connected

Winmor TNC receiving test

to RMS Trimode and to RFSM-8000 (can act as a server) and a IC-7300 connected to the RFSM-2400 and RMS Express with Winmor TNC.

I sent a jpeg file in size of 56.0 KB (57,344 bytes or 448.000 bits) with RFSM-2400 and with RMS Express via Winmor TNC.

The radios were set on 51 MHz, on dummy loads at 5W with a distance of about 1 m between them.  Both were on Wide and the signals on S-meter were peaking S3-S5. The modulation was set to not activate the ALC.

The results were astonishing! Via RMS Express, I sent the file in about 20 minutes.
Using RFSM-2400 the same file took less than 4 minutes...

So, the quick and dirty test have some conlusions:

1. When e-mail is important, Winlink + Winmor TNC is the one. There are many iGates on HF and is impossible to miss one, especially if you use the VOACAP tables to estimate the best channel for the given day and hour.

RFSM-2400 receiving private file (mail)

2. Do not try to send big attachements via Winlink! Instead, focus on smaller files, plain text or, if attachements are mandatory, use a good compression software.

3. If ad-hoc networks are the scope, RFSM is the best! You can define a FTP directory and  mailboxes  for the radio stations and each station can upload emails download their own. The FTP is very usefull for sharing files from one station to another. Good for a regional or national Emergency network.
A plus for RFSM-2400 is the chat and beacon mode!