- 1. [Amps] GU81-M on highbands (score: 1)
- Author: "Thomas Hoeppe" <thomas.hoeppe@asamnet.de>
- Date: Sun, 11 Jan 2009 07:15:25 +0100
- Has anybody used a single or a pair of GU81-M on highbands? Of course I see the problems with the high output capacitance, but there can be solutions like L-tuning or a small L before between tube an
- /archives//html/Amps/2009-01/msg00081.html (6,469 bytes)
- 2. Re: [Amps] GU81-M on highbands (score: 1)
- Author: DAVE WHITE <mausoptik@btinternet.com>
- Date: Sun, 11 Jan 2009 12:03:30 +0000 (GMT)
- Hi Tom - Somewhere I have a circuit from a Hungarian amateur that uses a single GU81M on 80-15m. I'll try to find it (a major operation in my library, and not one guaranteed of success!!) and scan i
- /archives//html/Amps/2009-01/msg00082.html (7,442 bytes)
- 3. Re: [Amps] GU81-M on highbands (score: 1)
- Author: "Alex Malyava" <alex.k2bb@gmail.com>
- Date: Sun, 11 Jan 2009 12:51:38 -0500
- there is an EX8A schematic - pair of GU81M with double pi-networks - one of them instead of plate choke. that amp works up to 10m no problem and gives 3kW out. http://www.cqham.ru/HiFi_Contester_EX8A
- /archives//html/Amps/2009-01/msg00083.html (8,605 bytes)
- 4. Re: [Amps] GU81-M on highbands (score: 1)
- Author: "Thomas Hoeppe" <thomas.hoeppe@asamnet.de>
- Date: Sun, 11 Jan 2009 19:05:18 +0100
- Thanks for all infos! The EX8A design is going an interesting way. If I understand it right the main trick is using L matching for the higher bands (C plate is already "in the tubes"), and the tuned
- /archives//html/Amps/2009-01/msg00084.html (10,493 bytes)
- 5. Re: [Amps] GU81-M on highbands (score: 1)
- Author: DAVE WHITE <mausoptik@btinternet.com>
- Date: Sun, 11 Jan 2009 18:37:07 +0000 (GMT)
- Thanks for this, Alex. That really looks like a great amp! No wonder they're loud from EX8A !! cheers Dave there is an EX8A schematic - pair of GU81M with double pi-networks - one of them instead of
- /archives//html/Amps/2009-01/msg00085.html (9,141 bytes)
- 6. Re: [Amps] GU81-M on highbands (score: 1)
- Author: "Peter Voelpel" <df3kv@t-online.de>
- Date: Sun, 11 Jan 2009 20:08:49 +0100
- I donīt see anything special with the Pi-net circuit. It is common practise to use fixed anode capacitors (including internal C) when using a roller inductor, in that case to have a separate 10m coil
- /archives//html/Amps/2009-01/msg00086.html (11,578 bytes)
- 7. Re: [Amps] GU81-M on highbands (score: 1)
- Author: "Alex Malyava" <alex.k2bb@gmail.com>
- Date: Sun, 11 Jan 2009 18:53:23 -0500
- I can briefly translate that article, if you interested in that schematic. that article covers several key points: 1. "old" GU81M tube is not outdated and still good for linear amplifiers 2. tube, de
- /archives//html/Amps/2009-01/msg00091.html (11,526 bytes)
This search system is powered by
Namazu