We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Subject / Started by Last post
1 Replies
261 Views
Last post October 24, 2025, 1139 UTC
by ChrisSmolinski
3 Replies
1157 Views
Last post June 21, 2025, 1316 UTC
by N2MLP
6 Replies
987 Views
Last post January 04, 2025, 0430 UTC
by Professor
1 Replies
557 Views
Last post April 20, 2025, 1723 UTC
by N2MLP
3 Replies
2086 Views
Last post June 07, 2025, 1242 UTC
by N2MLP
5 Replies
680 Views
Last post November 12, 2024, 0406 UTC
by Quasar
0 Replies
272 Views
Last post October 21, 2025, 1532 UTC
by ChrisSmolinski
3 Replies
418 Views
Last post October 11, 2025, 1901 UTC
by N2MLP
5 Replies
1592 Views
Last post September 01, 2025, 0432 UTC
by Markokpik
2 Replies
573 Views
Last post December 10, 2024, 0352 UTC
by Quasar
0 Replies
607 Views
Last post March 19, 2025, 0330 UTC
by Radiouser
4 Replies
879 Views
Last post July 23, 2025, 0408 UTC
by Andrew Yoder
4 Replies
1669 Views
Last post September 06, 2025, 1037 UTC
by ChrisSmolinski
5 Replies
819 Views
Last post July 03, 2025, 0435 UTC
by osiris
6 Replies
1613 Views
Last post April 12, 2025, 0433 UTC
by newmanm
4 Replies
1135 Views
Last post May 09, 2025, 0356 UTC
by Molvania Poacher
9 Replies
1923 Views
Last post May 25, 2025, 1711 UTC
by Tony_Pavick
4 Replies
1157 Views
Last post January 27, 2025, 0326 UTC
by Quasar
7 Replies
2199 Views
Last post May 22, 2025, 1247 UTC
by Tony_Pavick
0 Replies
445 Views
Last post January 08, 2025, 0244 UTC
by Radiouser

 

Normal Topic
Hot Topic (More than 15 replies)
Very Hot Topic (More than 25 replies)

Locked Topic
Sticky Topic
Poll


HFUnderground T-Shirt
HFUnderground House Flag
by MitchellTimeDesigns