We check all the links at least once per month. We guarantee that 99% of the links are operational or flagged as "Out of order". Non working links are first flagged as "Out of order". If the link stays dead we remove it later from the list after an unsuccessful attempt to find out a new address.
Radio monitoring company
World Data Center of Sunspot Index
(FR)
But also 2 m, 70 cm and microwaves
by YT6A
QSL Manager News
PC software project for weak signal reception
University of Twente PI4THT
Solar Cycle by VE3EN
by NASA
From the Royal Observatory of Belgium
by DL9QJ
Also log program, etc.
Freeware for audio analysis by DL4YHF
Small Practical Innovation: CTSS and DTMF coder/encoder, ATV, Packet, etc. (NL)
The Finnish Amateur Radio League
Suomen Radioamatooriliitto (FINLAND)
Sveriges Sündaramatürer
Modules and sub units for VHF and up
Modules and sub units for VHF and up
Modules and sub units for VHF and up
VHF/UHF/SHF Equipment and Parts
by WB8FSV
Contest program from EI5DI > freeware - supports UBA contest