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Total 439 documents matching your query.

321. Re: [Amps] FCC Denies Expert Linears' Request for Waiver of 15 dB Rule (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sat, 31 Dec 2016 06:55:25 -0600
<<Great post, Rob! Like many hams, especially older ones, I started down the learning path before I started high school. 60 years later, I'm still trying to learn new stuff, and to better understand
/archives//html/Amps/2016-12/msg00538.html (9,400 bytes)

322. [Amps] Decline of homebrewing? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Tue, 3 Jan 2017 05:17:32 -0600
All this demonstrates is that there are two ham radios, and some of you inhabit a world foreign to mine. In my ham radio, nearly everyone I know is a "ham in a basement with a soldering iron." Buildi
/archives//html/Amps/2017-01/msg00033.html (7,520 bytes)

323. Re: [Amps] Decline of homebrewing? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Wed, 4 Jan 2017 19:00:54 -0600
You need a lot more than that. Go to hamfests and look for and start buying up QSTs from before around 1955, ditto for handbooks, don't overlook tube manuals, the RCA Redbook, IIT Engineers Handbook
/archives//html/Amps/2017-01/msg00066.html (9,737 bytes)

324. Re: [Amps] Decline of homebrewing? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Thu, 5 Jan 2017 05:40:20 -0600
That's like the term "homebrewed dipole" an insult to anyone who actually builds a major piece of equipment such as a transmitter. In the days before these manufactured assemblies and dipoles were m
/archives//html/Amps/2017-01/msg00079.html (8,302 bytes)

325. Re: [Amps] rich Richard - tiny antenna (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Tue, 11 Apr 2017 04:47:50 -0500
This sounds like the comments of the folks who are slaves to coax and have multitude of dipoles up to cover HF. Or, they try cage dipoles to cover 80 m. The lengths the plastic radio/auto tuner crow
/archives//html/Amps/2017-04/msg00060.html (10,084 bytes)

326. Re: [Amps] Entry level license (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Fri, 28 Apr 2017 11:39:00 -0500
Which is perfectly fine but it underscores my opinion that there should be established a two way or land mobile radio service for people who have no interest in the radio art but want to be able to
/archives//html/Amps/2017-04/msg00381.html (9,033 bytes)

327. Re: [Amps] Pole pigs removed from oil ?? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Mon, 6 Nov 2017 08:39:32 -0600
I had a hunch someone would bring up PCBs sooner or later. The hysteria over PCBs is blown way way out of proportion, along with asbestos, lead in paint, RF exposure and a few other things. All of th
/archives//html/Amps/2017-11/msg00028.html (8,606 bytes)

328. Re: [Amps] Henry 2k-4 HV inductor (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Wed, 13 Dec 2017 05:19:53 -0600
Forget the tuned choke stuff, that's been shown to be unreliable. If you want a choke input filter, get a 10 henry choke and follow it with a bypass oil cap of at least 8 mfd rated for the B+ with so
/archives//html/Amps/2017-12/msg00095.html (7,795 bytes)

329. Re: [Amps] NXP 65V LDMOS 1K80H-1800W (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Tue, 26 Dec 2017 11:15:07 -0600
For some tube types that happened decades ago. But you can still find plenty of good 810s etc. decades later. In other words, what happens when no tube of any type is made? Answer: Not much, except
/archives//html/Amps/2017-12/msg00160.html (8,720 bytes)

330. Re: [Amps] Defining CCS (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Tue, 2 Jan 2018 11:38:13 -0600
A manufacturer could make an amp for hams that is N watts CCS. But it would be big, heavy and noisy and cost at least $10,000. And it would not have any bells and whistles. Today's ham wants a little
/archives//html/Amps/2018-01/msg00014.html (8,309 bytes)

331. [Amps] Defining CCS (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Wed, 3 Jan 2018 05:25:38 -0600
It's not too easy to design a pi output network that has a Q of 12 from 160 through 10 meters. Usually for a RF amplifier that is band switched, output (efficiency) suffers, usually at the ends of th
/archives//html/Amps/2018-01/msg00027.html (7,659 bytes)

332. Re: [Amps] Plate Choke Issue (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Fri, 5 Jan 2018 16:45:18 -0600
There are a number of factors affecting choice of plate choke. Most hams know that series resonances must be keep safely out of the ham bands for which the RF amplifier will operate in. It must also
/archives//html/Amps/2018-01/msg00054.html (10,643 bytes)

333. Re: [Amps] Commander HF 2500 (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Thu, 25 Jan 2018 11:44:02 -0600
A friend of mine and I got into an old Command amp to fix a problem a friend of ours was having with it. Can't remember if it was a one or two tube amp, but I came away being glad I never owned one.
/archives//html/Amps/2018-01/msg00140.html (7,883 bytes)

334. Re: [Amps] Alpha 77D anode choke swap? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Mon, 16 Apr 2018 08:05:46 -0500
I have doubts about 50 microhenries being adequate for 80 m. Well, it might be okay if you used a tremendous amount of bypass capacitance but I'd prefer more inductance, less capacitance. A couple q
/archives//html/Amps/2018-04/msg00041.html (8,656 bytes)

335. [Amps] Alpha 77D anode choke swap? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Tue, 24 Apr 2018 12:32:47 -0500
No pure resistive component to the imaginary number. Anything else? wire. It can handle more current. That doesn't reduce RF voltage to the power supply. 1500 pf @ 15 KV HEC doorknob cap. The 4700 p
/archives//html/Amps/2018-04/msg00053.html (9,348 bytes)

336. Re: [Amps] Alpha 77D anode choke swap? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Mon, 30 Apr 2018 08:31:28 -0500
Exactly what math is this? Tell that to VE7RF You are correct, however that technique is usually applied in circuits such as extremely broad banded RF preamps and audio amplifier bypass to cover a f
/archives//html/Amps/2018-05/msg00000.html (8,045 bytes)

337. Re: [Amps] Lube for roller inductor (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Fri, 3 Aug 2018 12:13:47 -0500
For contact surfaces, usually sliding metal to metal contact, try grease impregnated with silver. Use very small amounts because it doesn't take much and the stuff's expensive. Rob K5UJ _____________
/archives//html/Amps/2018-08/msg00013.html (7,982 bytes)

338. [Amps] Plate choke design L? (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sat, 8 Dec 2018 11:17:08 -0600
http://www.somis.org/add-160m.html scroll down to anode chokes: http://www.somis.org/D-amplifiers4.html 73 Rob K5UJ _______________________________________________ Amps mailing list Amps@contesting.c
/archives//html/Amps/2018-12/msg00049.html (7,148 bytes)

339. Re: [Amps] door knob capacitors needed (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Thu, 20 Dec 2018 07:54:33 -0600
Two points about the Russian doorknobs: 1. My expereince has been that the threaded ends twist off easily. Be careful and don't over-tighten. 2. They are metric so brass screws from Ace Hardware won'
/archives//html/Amps/2018-12/msg00096.html (7,910 bytes)

340. [Amps] Plate Loading Padding Caps (score: 1)
Author: Rob Atkinson <ranchorobbo@gmail.com>
Date: Sat, 22 Dec 2018 11:38:31 -0600
You don't need NP0 temp coefficient. A ceramic RF cap rated for the current and voltage is needed. The temp. coefficient can be N750 or even N3300 if the cap can handle the current and v. They are h
/archives//html/Amps/2018-12/msg00101.html (7,974 bytes)


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