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
0 Replies
1049 Views
Last post July 22, 2023, 1801 UTC
by ThaDood
Building an HF amplifier

Started by Matt285

6 Replies
5904 Views
Last post April 17, 2021, 2022 UTC
by redhat
1 Replies
2635 Views
Last post September 08, 2016, 1533 UTC
by Zazzle
2 Replies
2024 Views
Last post December 08, 2020, 1603 UTC
by syfr
2 Replies
1903 Views
Last post May 02, 2022, 0527 UTC
by ThaDood
7 Replies
5009 Views
Last post November 15, 2019, 1935 UTC
by redhat
13 Replies
26406 Views
Last post January 13, 2014, 0336 UTC
by ff
4 Replies
3195 Views
Last post June 04, 2020, 1923 UTC
by syfr
13 Replies
9444 Views
Last post February 22, 2020, 0227 UTC
by KaySeeks
1 Replies
2117 Views
Last post September 09, 2023, 1537 UTC
by Teotwaki
1 Replies
2272 Views
Last post April 12, 2021, 1305 UTC
by Beerus Maximus
6 Replies
3470 Views
Last post May 04, 2023, 1827 UTC
by W9RAN
14 Replies
8606 Views
Last post October 08, 2019, 0002 UTC
by redhat
Class D V2.0

Started by OgreVorbis « 1 2 »

17 Replies
8879 Views
Last post June 26, 2019, 1844 UTC
by Stretchyman
8 Replies
6346 Views
Last post August 11, 2018, 0715 UTC
by muromdx
16 Replies
9065 Views
Last post November 08, 2017, 1018 UTC
by Zazzle
2 Replies
2269 Views
Last post July 20, 2023, 2228 UTC
by Quinta
2 Replies
8023 Views
Last post August 20, 2013, 0245 UTC
by ff
14 Replies
35555 Views
Last post April 21, 2025, 1632 UTC
by europirate
Corsette Transmitter

Started by Intruder « 1 2 »

18 Replies
9989 Views
Last post February 14, 2019, 1525 UTC
by Intruder

 

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