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References: [ +subject:/^(?:^\s*(re|sv|fwd|fw)[\[\]\d]*[:>-]+\s*)*\[Amps\]\s+Dual\s+tetrode\s+in\s+grounded\s+grid\s*$/: 14 ]

Total 14 documents matching your query.

1. [Amps] Dual tetrode in grounded grid (score: 1)
Author: Glen Zook <gzook@yahoo.com>
Date: Wed, 11 Feb 2009 10:44:00 -0800 (PST)
Although not a "high powered" amplifier I am thinking of trying to use a 5894 (dual tetrode that is the next step up from the 829B) in grounded grid rather than the "normal" grid driven configuration
/archives//html/Amps/2009-02/msg00324.html (8,441 bytes)

2. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: Bill Fuqua <wlfuqu00@uky.edu>
Date: Wed, 11 Feb 2009 14:17:42 -0500
The problem is that the beam forming plates are connected to the cathode. That by-passes the shielding between the plate and cathode done by the grids. You may have instability. In the case of some o
/archives//html/Amps/2009-02/msg00325.html (10,123 bytes)

3. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: "Carl" <km1h@jeremy.mv.com>
Date: Wed, 11 Feb 2009 14:38:01 -0500
Why not use a pad inside of the amp at the input link or tap? Looking at the tube specs Im not sure the 5894 screens are up to GG use. Its pretty close to a pair of 6146's in that respect. In AB grid
/archives//html/Amps/2009-02/msg00326.html (10,240 bytes)

4. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: Glen Zook <gzook@yahoo.com>
Date: Wed, 11 Feb 2009 12:16:46 -0800 (PST)
Using an attenuator pad at the input is what I was considering. Of course I would rather use the power from the transmitting converter for something other than generating heat. Basically I was seeing
/archives//html/Amps/2009-02/msg00331.html (9,612 bytes)

5. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: Glen Zook <gzook@yahoo.com>
Date: Wed, 11 Feb 2009 12:26:20 -0800 (PST)
I had forgotten about the beam forming plates! Just like the 1625 versus the 837 although some brands of the 1625 had the beam forming plates connected outside of the glass envelope and therefore can
/archives//html/Amps/2009-02/msg00332.html (9,086 bytes)

6. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: "Gary Schafer" <garyschafer@comcast.net>
Date: Wed, 11 Feb 2009 15:51:25 -0500
The other problem with it is you can't run the plates in push pull and drive the common cathode as it will cancel the output. You would need to run the plates in parallel but then there is the proble
/archives//html/Amps/2009-02/msg00334.html (10,130 bytes)

7. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: "Carl" <km1h@jeremy.mv.com>
Date: Wed, 11 Feb 2009 15:38:36 -0500
RG-58 also makes an excellent attenuator Carl KM1H _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
/archives//html/Amps/2009-02/msg00340.html (10,440 bytes)

8. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: "Carl" <km1h@jeremy.mv.com>
Date: Wed, 11 Feb 2009 15:45:09 -0500
And there is always the pot in the screen lead B+ of the 6360 trick. Just dial in the drive you want. I use a screen pot in the HA-6 5894 to drive a NCL-2000 at 15W or a converted Alpha 76PA at 100W.
/archives//html/Amps/2009-02/msg00341.html (10,502 bytes)

9. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: Glen Zook <gzook@yahoo.com>
Date: Thu, 12 Feb 2009 09:06:16 -0800 (PST)
A couple of others pointed out the common cathode problem to me in direct E-Mails as well as the beam forming plates. As such, back to the original push-pull design! Glen, K9STH Website: http://k9sth
/archives//html/Amps/2009-02/msg00362.html (7,480 bytes)

10. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: Glen Zook <gzook@yahoo.com>
Date: Thu, 12 Feb 2009 09:38:06 -0800 (PST)
The only problem with using RG58/U is that you are going to have a pretty large coil. Also, resistors are definitely a lot cheaper even though I buy RG58/U in 500 foot spools for making the interconn
/archives//html/Amps/2009-02/msg00368.html (9,209 bytes)

11. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: "Carl" <km1h@jeremy.mv.com>
Date: Thu, 12 Feb 2009 14:57:09 -0500
I thought this was for 222 mHz? RG-58 loss is about 8dB per 100' and you dont need that much attenuation. If you want short try RG-174 or RG-178. I had to go the other way with my HA-2 and HA-6 since
/archives//html/Amps/2009-02/msg00376.html (10,096 bytes)

12. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: Glen Zook <gzook@yahoo.com>
Date: Thu, 12 Feb 2009 12:56:21 -0800 (PST)
I am still going to need at least 6 dB attenuation and that would mean at least 75 feet of RG58/U at a cost of just over 30 cents a foot. Compare that with resistors which would total well under a do
/archives//html/Amps/2009-02/msg00378.html (9,089 bytes)

13. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: Glen Zook <gzook@yahoo.com>
Date: Thu, 12 Feb 2009 15:15:35 -0800 (PST)
I am VERY familiar with the characteristics of RG58/U. In fact, I used to buy it by the 1000 foot spools and use it for "leaky line" antennas for 960 MHz 47 CFR Part 15 installations in places like w
/archives//html/Amps/2009-02/msg00386.html (10,871 bytes)

14. Re: [Amps] Dual tetrode in grounded grid (score: 1)
Author: Glen Zook <gzook@yahoo.com>
Date: Thu, 12 Feb 2009 20:06:43 -0800 (PST)
Agreed! But your comment about RG58/U brought it on. Anyway, enough on the subject. Glen, K9STH Website: http://k9sth.com _______________________________________________ Amps mailing list Amps@contes
/archives//html/Amps/2009-02/msg00398.html (12,969 bytes)


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