Links

Great overview of all Tandberg products
For receivers, chose radios. You can select language down at the right.
https://nrhf.no/Skjemabank/tb_froplacd.php

Components
www.mouser.com
www.reichelt.com

Great vintage audio restoration channels on Youtube
Electronics Old and New by M Caldeira (expert restoration of vintage radios, and more)
https://www.youtube.com/channel/UC1czABA87SroDeBAqsk1TDA
D-Lab (funny guy, tubes and solid state)
https://www.youtube.com/user/dlab500
Xraytonyb (very interesting and informative, tubes and solid state)
https://www.youtube.com/channel/UChTN8got77QeKPFRmTJ0teg
Mr Carlson’s lab (maybe the most famous electronics guy? Not only audio)
https://www.youtube.com/user/MrCarlsonsLab
Uncle Doug (tubes mostly, very informative, has some superb lessons on tube basics)
https://www.youtube.com/user/Stratosaurus1
Blueglow electronics (very informative, not only audio)
https://www.youtube.com/channel/UCVXv8_dfJjqWluEFktmv12A
Tomtektest (superb course on tubes, 6 videos, link goes to playlist)
https://www.youtube.com/playlist?list=PL2u6aYAXZ0Z9zKCWzSNPCnPaFXVkPXmgG

Other interesting audio and audiophile channels on Youtube
Thomas and Stereo (I like this guys reviews, very high-end oriented)
https://www.youtube.com/channel/UCMVtSHXafOEcFN10FYygDTA
Anadialog (vintage audiophile, how to bring out the best in your vintage gear)
https://www.youtube.com/channel/UCaBStRQQh2sN2K_Ay-uXwUA

Speaker restoration service
The restoration service I have been using
https://www.anapeachloudspeakerrestoration.co.uk/

Tandberg service and repairs
http://rdetandberg.co.uk/
You can also find links to other repair shops on the International Tandberg Forum.

Information
https://snw.lonningdal.no/h10compare.php (comparisons between different Tandberg models, very interesting!)
http://sportsbil.com/tandberg/ (the place for Tandberg manuals)
https://www.hifiengine.com/ (manuals)
http://www.nrhf.no/index.php (Norwegian radio association, lots of info, in Norwegian)
https://www.radiomuseum.org/act_main.cfm (data)
https://museumofmagneticsoundrecording.org/ManufacturersTandberg.html (great list of Tandberg tape recorders)

Forums
www.tandbergforum.com (the international Tandberg forum, ask anything)
https://www.hifisentralen.no/forumet/vintageavdelingen/ (in Norwegian)

About Tandberg
http://elektronikknett.no/Artikkelarkiv/2018/Oktober/Motpolene-Vebjoern-Tandberg-og-Jens-Christian-Hauge (newspaper article, Norwegian)
https://www.youtube.com/watch?v=2Wq-HBar_Bk (great documentary about the company Tandberg, in Norwegian)