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Re: G3SEK TRIODE BOARD on eBay
Thanks for that insight, Reid. With all that?being said, the electronic methods for control and protection of triode and tetrode amplifiers haven't changed....Ian's circuits, from an electronics standpoint, are still valid. That being the case, duplicating the circuits with modern components on new boards is entirely feasible for someone with PCB design experience. Whether or not anyone is willing to take up the project is really the crux of the matter, and support of the product is an option entirely up to the person doing the work. I'm not willing to take on that project, but it seems likely to me that someone?would. Thanks, Robin Midgett K4IDC On Mon, Jan 13, 2025 at 10:02?AM Brandon DX via <rfburnz=[email protected]> wrote:
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Re: G3SEK TRIODE BOARD on eBay
I was reminded there is another source for boards to use with a triode OR tetrode, one built in France
A couple of years ago I was in a discussion about using one of them on a larger tetrode in Europe.
Not certain how that turned out but I bought one of the boards but never completed the project.
Check out the link, it may come up in French but there is a button to translate to English.
?
Dom is an active designer and quite friendly and able to communicate despite the language barrier.
This should then be considered a new source of boards for use with tube linears.?
73,
Reid W6MTF |
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Re: G3SEK TRIODE BOARD on eBay
I contacted a friend of Ian's and he dialed him up and asked to comment on the subject at hand.
Ian said he basically was unable to help, here's his reply
?
"There have been a few inquiries about reissuing the boards, but I'm afraid that is no longer workable. Here's why: 1. Those boards were designed more than 25 years ago, and many of the components are now obsolete. This was already becoming a problem when I closed the business, and of course has only become worse. Also the software that I used to create the boards and schematics is way out of date, so I can't even edit the files any more. 2. Even if by some miracle I could find the Gerber files, all of those other changes mean that re-issued boards would in reality be new products, each with its own new range of support issues. I always took the "lifetime support" commitment very seriously, but today I don't even have the amplifiers or the test rigs to simulate faults or provide support. Too many things have changed." ? That's life, things change. 73 Reid Brandon? W6MTF ? |
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Re: Keying interface
It looks like my drawing will work. I used a 2N2222 to switch it. This is done on a perf board only. The amp keying is 25 volts?@ 60 mA so I'll have to determine the 2N2222 base resistor. I'm measuring just under 7mA on the diode side which is what the radio will see. I would like it down to 5 or 6mA.? To get the voltage and current down on the diode side I made a voltage divider?which brings the voltage down to around 6 1/2, which is where I'm measuring?the diode current at just under 7mA.? Still working at it. Bob W4JFA On Sun, Jan 12, 2025 at 4:27?PM Bob via <W4JFABob=[email protected]> wrote:
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Re: Keying interface
Ron, Thank you. I'm trying to learn these optocouplers?so I need to figure out on my own. Attached is my drawing. After looking around I may order? a few 4N25's. Bob W4JFA On Sun, Jan 12, 2025 at 10:24?AM Ron via <rolexa=[email protected]> wrote:
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KD9SV Ft. End Protectr
开云体育Years ago Gary made a relay-driven protector when it was seen that a large RF signal could damage the circuitry of the transceiver’s RX2 port. ? It turned out to be an excellent RF amplifier keying driver as the high quality of the driver relay provided a worthwhile isolation. ? There are a number of available products these days, I hear. Like ?I.C.E. Products, the KD9SV stamp is to investigate. ? Hal W4HBM ? ? |
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Re: Keying interface
Another simple almost complete interface costing a few $$:? An Arduino 12V relay module.? It has an optoisolator input driving a reed relay.? 12V power, and a couple cables are all that's needed to make the interface.? I've used it to connect my Ten Tec Jupiter to my Heathkit HL2200 linear.??
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Keying interface
Hi all, Since I'm now retired I have time to goof off. I was trying to design an amplifier keying interface using an optocoupler. I don't need one since I already?built a few using BJT's?and/or darlingtons so this is just killing time on a rainy day. I have an MCT61. I haven't been able to figure out the datasheet since it seems to list things in a different way. The?datasheet is probably fine, it's just I have virtually no experience with optocouplers. So using the DATA DIN on the back of my 850 and 870 I need to keep the current draw on that DIN under 10 mA so my target is 6 mA.? I made a voltage divider?to keep the voltage down to the opto and also keep the current down on the radio's 12 volt supply. I did hit my target of 6 mA and also I measured 6 mA on the diode side of the opto but on the transistor side of the opto? I measured 85 ohms from C to E when turned on so I feel the?opto was not completely turning on the transistor side. I was hoping to see zero ohms when turned on, not 85 or so. What I was going to do next is use a regular switching BJT driven by the transistor side of the opto to do the amplifier keying/switching. I haven't got to that part of this experiment yet but my gut feeling is I don't have the correct optocoupler for this project. Again I need to keep the current draw on the Kenwood radio's DIN plug at 6mA so my thinking is I need an opto that will completely saturate the transistor side with 6mA current on the diode side and it doesn't look like what I have can do that. Again, this is just for fun but if I'm successful?I'll make one for my amps. Am I on the right track? Thanks for reading. Bob W4JFA |
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Re: G3SEK TRIODE BOARD on eBay
开云体育Hullo Tracey and the Group, ? Does anyone chat about with Ian, GM3SEK? ? He’s a member of the Oxford University Radio club, and still active on VHF, I believe. ? Perhaps he might “Pass along the ball” to the next generation, seeing as how his design has been growing in popularity. ? Hal Mandel W4HBM |
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Re: G3SEK TRIODE BOARD on eBay
开云体育RE: GM3SEK Tetrode Controller????????????? ? Somewhere in the collection of 50 some years of building amplifiers there exists a new, pristine collection of Tetrode Controller stuff. ? There are two boards, unpopulated as yet. ? If I wanted to duplicate these boards where is a recommended tech? ? TNX ? Hal Mandel W4HBM |
Robin Midgett
Brandon DX
Bob
HaL Mandel