Commander HF-2500
This is a real long shot. I have an old Commander HF-2500 which I love very much. It is Serial Number 186 and it conforms with the printed manual and schematic of June 1990. However, there is no
By
Alek Petkovic
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#40972
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Re: Drake L-7
Hi Francois, I did not document my changes and sold the amp a few years ago. I remember the green capacitor (B) but not (A). That could easily be a memory leakage on my side but I couldn¡¯t find it
By
Evert Bakker
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#40971
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Re: Drake L-7
Hello I am weak in technology (I am 75 years old). It seems to me that you are pointing out the two curious plate capacitors A = C41 (47 pF) and B = C42 (307 pF). Could you give me, precisely, the
By
Fran?ois
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#40970
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Re: Drake L-7
The reason is in this message /g/ham-amplifiers/message/40898 -- F1AMM Fran?ois De la part de Evert Bakker via groups.io Envoy¨¦ : samedi 25 janvier 2025 19:38
By
Fran?ois
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#40969
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Re: Drake L-7
I recently bought this L 7 (about $1000) from an OM who used it very little. It has the serial number 672. On this device, the air is sucked from the bottom of the case by a kind of scoop. It is a
By
Fran?ois
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#40968
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Re: Drake L-7
Why do you want to see these tubes all the time? It is the most reliable amp I¡¯ve had. You can push this amp to all its limits and beyond, it just won¡¯t die. Even when it starts to stink like
By
Evert Bakker
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#40967
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Re: Drake L-7
It seems your lid or top sheet metal has been changed. Mine has holes and I can see the tubes.
By
mike repinski
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#40966
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Re: Drake L-7
The top sheet metal is a solid sheet metal. You can see, very badly, through the fan. Removing the top panel: ok. To do a short test, it is a solution but in operation it is not reasonable, if only
By
Fran?ois
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#40965
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Re: Drake L-7
Take the top-cover off and use something to push the rod down so the HV will pass through. As long as you know what you are doing ¡ (I shorted that switch) BUT TAKE CARE. There is no room for
By
Evert Bakker
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#40964
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Re: Drake L-7
You should be able to see them thru the top of the amp turning red.
By
mike repinski
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#40963
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Drake L-7
Hello I am in the process of putting a Drake L 7 amplifier back into operation. I was advised on this forum to bring the anodes of the 3-500Z to red to maintain the quality of the vacuum. After
By
Fran?ois
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#40962
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Re: Two tones test generator
In the same way that there are synthetic white noise generators, from a pseudo-random code, are there synthetic pink noise generators? This pink noise modulating in SSB seems to me to be a very good
By
Fran?ois
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#40961
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Re: Two tones test generator
Excellent idea...... and I had forgotten all? about it.? ?My Behringer DEQ-2496? ( 24 bit - 96 khz)? mastering processor has a pink noise generator in it.? ?I checked my old notes, and when fed
By
Jim VE7RF
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#40960
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Re: AL-82 Date of Manufacture
I have a 2014 AL-82 and two of the components inside have manufacture dates on them. One was the power supply and I don't remember the other might have been the blower. [email protected]> wrote:
By
Matt KA6JAR
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#40959
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AL-82 Date of Manufacture
Hello, Can the vintage or date of manufacture be determined from the serial number on an Ameritron AL-82? Thanks and 73, Garry - K4OR
By
Garry - K4OR
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#40958
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?Southeastern VHF Society 2025 Conference Announcement & Call For Papers
#2MAmplifier
? Southeastern VHF Society 2025 Conference Announcement & Call For Papers Quality Inn , 3095 Wilma Rudolph Blvd, Clarksville, TN 37040 April 4th and 5th, 2025 Papers and presentations are solicited
By
Robin Midgett
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#40957
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Re: Two tones test generator
Another way to check for linearity is to use pink noise as an input: all frequencies in the pass band simultaneously. A perfectly linear system would reproduce exactly the input spectrum as the
By
Kim Elmore
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#40956
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Re: Two tones test generator
Be careful when conducting 2 x tone tests.? You can easily manipulate / skew? the results by? manipulating the tone spacing.? ?Manufacturer's would do just that, years ago, to minimize IMD3 and
By
Jim VE7RF
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#40955
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Re: Two tones test generator
XCVR is an abbreviation for Transceiver MK-V is a Yaseu Transceiver L4B is a model of an old Drake amplifier DENON test cds are Compact Disks for DENON test equipment Abbreviations and model
By
Dave w6de
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#40954
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Re: Two tones test generator
Dimanche, 19 Janvier, 2025; 1148 EST Dear Francois, XCVR = Transceiver, a Transmitter and Receiver in the same box. Often referred to as "Tx or TX," and " Rx or RX" thus: "TRX." MK-V = The Yaesu
By
HaL Mandel
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#40953
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