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
32 Replies
12808 Views
Last post October 10, 2018, 1207 UTC
by R4002
35 Replies
74514 Views
Last post September 28, 2019, 1435 UTC
by R4002
21 Replies
8389 Views
Last post August 10, 2018, 1700 UTC
by R4002
New here

Started by SBS01

1 Replies
2632 Views
Last post March 02, 2020, 0001 UTC
by Matt285
1 Replies
8874 Views
Last post October 14, 2015, 2320 UTC
by ChrisSmolinski
0 Replies
3870 Views
Last post December 11, 2014, 1022 UTC
by dxextra
1 Replies
2381 Views
Last post June 09, 2020, 0013 UTC
by Rob.
Mystery Signal

Started by Matt_B

2 Replies
3523 Views
Last post May 18, 2020, 1752 UTC
by Josh
0 Replies
1238 Views
Last post July 22, 2023, 2331 UTC
by TRI International
0 Replies
11962 Views
Last post August 01, 2019, 1908 UTC
by ChrisSmolinski
0 Replies
3320 Views
Last post August 09, 2019, 1143 UTC
by ChrisSmolinski
0 Replies
1565 Views
Last post February 20, 2024, 1229 UTC
by R4002
1 Replies
3510 Views
Last post December 18, 2024, 1208 UTC
by R4002
4 Replies
4173 Views
Last post January 30, 2020, 1336 UTC
by R4002
8 Replies
4578 Views
Last post October 13, 2023, 0223 UTC
by ~SIGINT~
0 Replies
8381 Views
Last post April 29, 2013, 1926 UTC
by w5cdt
0 Replies
4644 Views
Last post May 14, 2013, 2335 UTC
by w5cdt
0 Replies
1221 Views
Last post February 15, 2023, 1506 UTC
by R4002
L band monitoring

Started by Josh

0 Replies
3377 Views
Last post September 06, 2019, 1732 UTC
by Josh
0 Replies
3779 Views
Last post April 19, 2019, 1834 UTC
by Josh

 

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

Locked Topic
Sticky Topic
Poll


HFUnderground T-Shirt
HFUnderground Garden Flag
by MitchellTimeDesigns