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
2384 Views
Last post May 02, 2021, 0713 UTC
by prldx
0 Replies
1949 Views
Last post April 27, 2021, 1527 UTC
by Nielsbo
1 Replies
887 Views
Last post September 10, 2025, 2042 UTC
by nitroengine
2 Replies
4115 Views
Last post November 20, 2018, 0057 UTC
by NJQA
VLF and LF

Started by NJQA

2 Replies
3362 Views
Last post October 05, 2019, 0230 UTC
by NJQA
1 Replies
3330 Views
Last post March 19, 2017, 1402 UTC
by Skipmuck
3 Replies
5936 Views
Last post December 20, 2016, 0614 UTC
by Pigmeat
1 Replies
2356 Views
Last post June 03, 2022, 0509 UTC
by Shortwave_Listener
1 Replies
2211 Views
Last post August 21, 2020, 0736 UTC
by prldx
2 Replies
2481 Views
Last post January 09, 2022, 0204 UTC
by ~SIGINT~
3 Replies
2717 Views
Last post July 29, 2021, 1908 UTC
by ~SIGINT~
0 Replies
3940 Views
Last post March 17, 2025, 0427 UTC
by Robot Matrix
2 Replies
7023 Views
Last post January 21, 2025, 0522 UTC
by Robot Matrix
5 Replies
5142 Views
Last post February 22, 2019, 1851 UTC
by Brian
1 Replies
34534 Views
Last post July 31, 2019, 0232 UTC
by ulx2
5 Replies
8343 Views
Last post January 15, 2025, 0238 UTC
by n2avh
0 Replies
2485 Views
Last post March 18, 2017, 2336 UTC
by shadypyro
2 Replies
1682 Views
Last post September 07, 2022, 0212 UTC
by Sky
0 Replies
3481 Views
Last post March 23, 2017, 1430 UTC
by Static_Mantra
0 Replies
3541 Views
Last post January 19, 2019, 0511 UTC
by Strange Beacons

 

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

Locked Topic
Sticky Topic
Poll


HFUnderground T-Shirt
HFUnderground T-Shirt
by MitchellTimeDesigns