Search String: Display: Description: Sort:

Results:

References: [ +from:km1h@jeremy.qozzy.com: 394 ]

Total 394 documents matching your query.

101. Re: [Amps] What 811A's Should I Try to Find? (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Sun, 25 Jan 2015 15:13:55 -0500
Look for discoloration on the anode, it should be a nice flat black. Also no discoloration of the glass or those little filament support springs loose in the bottom...or little pieces of filaments. A
/archives//html/Amps/2015-01/msg00283.html (10,311 bytes)

102. Re: [Amps] 833A GG (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Mon, 26 Jan 2015 14:59:45 -0500
Heck I had a pair of 100TH's on 6M in the early 60's but no matter what I did with the bias or drive could I get high output and no splatter at the same time. At 3KV they glowed nice. Shortly after t
/archives//html/Amps/2015-01/msg00306.html (14,531 bytes)

103. Re: [Amps] 833A GG (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Mon, 26 Jan 2015 17:13:55 -0500
Thats worth more to a collector than chancing it is gassy and blow the filament. Carl KM1H -- From: "Fuqua, Bill L" <wlfuqu00@uky.edu> Sent: Monday, January 26, 2015 4:10 PM To: "Carl" <km1h@jeremy.q
/archives//html/Amps/2015-01/msg00308.html (16,201 bytes)

104. Re: [Amps] push pull or parallel ? (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Mon, 26 Jan 2015 17:21:17 -0500
In a series fed PP circuit the Tune cap has to stand off the full DC voltage plus the Peak RF. On AM that is 4X the DC voltage for spacing. Altho cap values in PP are lower they are dual sections wit
/archives//html/Amps/2015-01/msg00309.html (10,983 bytes)

105. Re: [Amps] push pull or parallel ? (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Mon, 26 Jan 2015 17:21:53 -0500
You can use a stub in the coax to get an easy 20-25dB additional second harmonic reduction. A lot less hassle in a mono band or just put a stub in individual antenna leads. Carl KM1H Hi, 160mtrs cont
/archives//html/Amps/2015-01/msg00310.html (9,098 bytes)

106. Re: [Amps] push pull or parallel ? (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Mon, 26 Jan 2015 17:21:58 -0500
Lower the Q for wider bandwidth and less need of a retune, you should be able to use a 6 Q and followed by coax stubs for 2nd and 3rd harmonics. Carl KM1H Hi, 160mtrs contest past and we need more po
/archives//html/Amps/2015-01/msg00311.html (12,710 bytes)

107. Re: [Amps] 833A GG (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Mon, 26 Jan 2015 18:19:53 -0500
You can always use a piece of regular solid dielectric coax or even hardline off the anode and then followed by a LV variable. I used a piece of RG-17 and a small mil surplus cap with about 1500-2000
/archives//html/Amps/2015-01/msg00313.html (9,940 bytes)

108. Re: [Amps] {Collins} Understanding Screen Current in a Tetrode (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Tue, 27 Jan 2015 20:17:53 -0500
Maximum allowable screen current is not the correct way. You tune for a screen current PEAK and then use the load control to reach a maximum RF output while keeping the screen current within limits,
/archives//html/Amps/2015-01/msg00324.html (13,490 bytes)

109. Re: [Amps] {Collins} Understanding Screen Current in a Tetrode (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Tue, 27 Jan 2015 21:26:57 -0500
I don't care for that JI answer since grid driven tetrodes are almost always run in AB1 where there is no grid current and in AB2 there is only a flicker of current on peaks but a lot more IMD. Tunin
/archives//html/Amps/2015-01/msg00325.html (16,088 bytes)

110. Re: [Amps] Topband: Elimination of Treadmill RFI on 160 meters (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Wed, 28 Jan 2015 11:17:07 -0500
Ive cleaned and used Artic Silver on several of my Astrons and other high heat devices. Learned that trick when overclocking PC's. Carl KM1H On both of my Astrons, I noticed that the output transisto
/archives//html/Amps/2015-01/msg00343.html (9,559 bytes)

111. Re: [Amps] What tube? (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Wed, 28 Jan 2015 14:03:27 -0500
The 4-400 in GG have less gain than a 3-500 and a pair is usually good for 1000W in a full GG SB-220 thru 10M at 100W drive unless they are tired pulls. I converted an ISM amp with a pair of them to
/archives//html/Amps/2015-01/msg00348.html (10,241 bytes)

112. Re: [Amps] {Collins} Understanding Screen Current in a Tetrode (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Wed, 28 Jan 2015 14:26:12 -0500
Since the screen is the weak link in the NCL-2000 I don't run mine or customers beyond 15-20ma in the SSB position for the pair and if the PO is a bit lower than the usual 1200W key down it not enoug
/archives//html/Amps/2015-01/msg00349.html (14,260 bytes)

113. Re: [Amps] Astron Power Supplies (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Wed, 28 Jan 2015 14:33:46 -0500
A scope may not have the resolution to see any. Ask someone with a SDR and built in spectrum analyzer to check the signal over a wide bandwidth such as DC to daylight. Carl KM1H Hang a scope on the o
/archives//html/Amps/2015-01/msg00350.html (10,247 bytes)

114. Re: [Amps] What tube? (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Thu, 29 Jan 2015 18:51:52 -0500
If you use care in selecting the filament transformer it can be self current limiting. The one in the SB-220 is a good example. Many HB and commercial amps start off with a "robust" transformer capab
/archives//html/Amps/2015-01/msg00370.html (18,456 bytes)

115. Re: [Amps] What tube? (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Thu, 29 Jan 2015 18:52:39 -0500
The 4-400 and GU-81M can both be run in GG. In a SB-220 with100W of drive you can expect 1000W due to a bit lower gain than the 3-500Z. Crank up the voltage at the same 100W and 1500W is likely attai
/archives//html/Amps/2015-01/msg00371.html (17,660 bytes)

116. Re: [Amps] What tube? (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Fri, 30 Jan 2015 17:23:46 -0500
Old 813's, 4-400A, and most any other post WW2 glass tube may benefit from the same regettring process as the 3-500, 572B, etc. Ive recovered many 211/VT4's, 809, 810, 8000, 8005, 813, 4-250/400's, a
/archives//html/Amps/2015-01/msg00379.html (10,656 bytes)

117. Re: [Amps] AL-1500 power relays (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Sun, 1 Feb 2015 19:48:02 -0500
That is a common fault on the senior series amps and the first thing to check is if the circuit is wired as per the schematic. Many are not and this goes back decades. I never cared for Ameritrons st
/archives//html/Amps/2015-02/msg00002.html (9,144 bytes)

118. Re: [Amps] Variac Question (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Tue, 3 Feb 2015 10:59:42 -0500
If it is rated at 120/240VAC it has the equivalent of a CT Carl KM1H Exactly. I'm almost positive that my 240 volt primary transformer does not even have a center tap. 73, Mike www.w0btu.com No you d
/archives//html/Amps/2015-02/msg00021.html (9,861 bytes)

119. Re: [Amps] Variac Question (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Tue, 3 Feb 2015 11:00:00 -0500
With such a marginal variac the DC dynamic regulation is going to be pretty poor. When all else fails consider a choke input at least until you can get a proper transformer, you will wind up with abo
/archives//html/Amps/2015-02/msg00022.html (12,189 bytes)

120. Re: [Amps] {Collins} Understanding Screen Current in a Tetrode (score: 1)
Author: "Carl" <km1h@jeremy.qozzy.com>
Date: Tue, 3 Feb 2015 11:00:12 -0500
There certainly is nothing new about the proper tuning procedure for a tetrode. The following was taken from the 1963 National NCL-2000 manual who also had plenty of prior experience building militar
/archives//html/Amps/2015-02/msg00023.html (12,224 bytes)

Current List: 101 - 120
Page: [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20]
This search system is powered by Namazu