K3 Variable amp keying delay >>not long enough!!??
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K3 Variable amp keying delay >>not long enough!!??
 
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The FAQ for the K3 promised a 0-50 ms amp keying delay. We got only 0-20 ms in the latest release. I don't think 20 ms is enough in my case, based on my primitive research. Several "experts" have said mine might need as much as 30-35 ms. My amp's relay is a 30 yr old Potter & Brumfield open frame model with a 120vac coil.
To make things worse, since the K3 will not switch 120vac, I must use another relay with a 12vdc coil in the line between the K3 and the amp, which in turn pulls in the P&B relay. This exacerbates the matter by taking even more time, and I'm afraid to try anything for fear it will damage the K3 and the amp. Am I wrong?? Anyone care to comment?? One of the many reasons I bought the K3 was to be able to operate at least semi break in CW and VOX with my old amp without hot switching, by virtue of having ample switching delay. I've waited months for the feature and am disappointed.. However, I hasten to add this: As a K2 user/owner/builder, I expected much in the K3. I got much more than I expected. I gave up a nice Icom Pro 3 for the K3 and don't miss the Pro 3 one iota. The K3 is unbelievable in what it can do and how superbly it does it. And getting new firmware is icing on the cake. But I sure wish I had 0-50ms amp delay capability! How about it, Wayne? George, N4YM K2 # 4758 K3 # 340 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: K3 Variable amp keying delay >>not long enough!!??
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Administrator
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George,
Before settling on a max of 20 ms we looked at a number of amplifiers and got input from several "experts. If yours (or others) really need more than 20 ms, I can increase the delay with some additional work. Please contact me directly if you find out any more about your particular delay time requirements. tnx Wayne N6KR On May 8, 2008, at 5:53 PM, George wrote: > The FAQ for the K3 promised a 0-50 ms amp keying delay. We got only > 0-20 ms in the latest release. I don't think 20 ms is enough in my > case, based on my primitive research. Several "experts" have said > mine might need as much as 30-35 ms. My amp's relay is a 30 yr old > Potter & Brumfield open frame model with a 120vac coil. --- http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: K3 Variable amp keying delay >>not long enough!!??
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In reply to this post by George-122
I would be tempted to replace the 120VAC relay with a dc relay and key it
directly from the rig. Don't forget to fit a diode across it to squash the back emf. This may have other ramifications and might not be this simple, but it's well worth consideration. David G3UNA The FAQ for the K3 promised a 0-50 ms amp keying delay. We got only 0-20 ms in the latest release. I don't think 20 ms is enough in my case, based on my primitive research. Several "experts" have said mine might need as much as 30-35 ms. My amp's relay is a 30 yr old Potter & Brumfield open frame model with a 120vac coil. To make things worse, since the K3 will not switch 120vac, I must use another relay with a 12vdc coil in the line between the K3 and the amp, which in turn pulls in the P&B relay. This exacerbates the matter by taking even more time, and I'm afraid to try anything for fear it will damage the K3 and the amp. Am I wrong?? Anyone care to comment?? One of the many reasons I bought the K3 was to be able to operate at least semi break in CW and VOX with my old amp without hot switching, by virtue of having ample switching delay. I've waited months for the feature and am disappointed.. However, I hasten to add this: As a K2 user/owner/builder, I expected much in the K3. I got much more than I expected. I gave up a nice Icom Pro 3 for the K3 and don't miss the Pro 3 one iota. The K3 is unbelievable in what it can do and how superbly it does it. And getting new firmware is icing on the cake. But I sure wish I had 0-50ms amp delay capability! How about it, Wayne? George, N4YM K2 # 4758 K3 # 340 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by wayne burdick
Some lack of communication between Greg and Wayne I expect regarding the published figures. Luckily, this is a simple thing to fix one would hope. I sent in a list of relay transit times on 2nd April.
It was quite clear that 20mS was needed for the smaller coaxial relays like the very commonly used CX540 and up to 50mS for the very high power relays that you might use on a 1.5kW 6m amplifier. I was surprised to discover the maximum delay was set to only 20mS as this is not enough; a margin is needed. The CX540 is common and http://www.nts-electronic.com/cx540d.htm tells me it takes 20mS to engage and 15mS to release. Tohotsu relays are very common. The CX230, CZX3500, CX600, CX800, CX140 and CX120 are often used in amateur applications (because they are cheap). They also all specify 20mS. For really high power SSB electronics (Germany) do a specialist range of relays. These specify 30mS for the HF400 series, 40mS for the HF500/1500 series and 50mS for the HF4000 series.
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Re: K3 Variable amp keying delay >>not long enough!!??
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In reply to this post by George-122
Hi George,
you are right with 20ms limit, it is also little bit short for complex system like VHF/UHF EME station or similar "extreme". But we can use TX INHIBIT if delay is not enough, signal for this can be genetated by some additional contacts of final relay. So I suppose there is way not only via TX DELAY. GL & 73! Lexa, ok1dst K3 #727 George napsal(a): > The FAQ for the K3 promised a 0-50 ms amp keying delay. We got only 0-20 ms in the latest release. I don't think 20 ms is enough in my case, based on my primitive research. Several "experts" have said mine might need as much as 30-35 ms. My amp's relay is a 30 yr old Potter & Brumfield open frame model with a 120vac coil. > > To make things worse, since the K3 will not switch 120vac, I must use another relay with a 12vdc coil in the line between the K3 and the amp, which in turn pulls in the P&B relay. This exacerbates the matter by taking even more time, and I'm afraid to try anything for fear it will damage the K3 and the amp. Am I wrong?? Anyone care to comment?? > > One of the many reasons I bought the K3 was to be able to operate at least semi break in CW and VOX with my old amp without hot switching, by virtue of having ample switching delay. I've waited months for the feature and am disappointed.. > > However, I hasten to add this: As a K2 user/owner/builder, I expected much in the K3. I got much more than I expected. I gave up a nice Icom Pro 3 for the K3 and don't miss the Pro 3 one iota. The K3 is unbelievable in what it can do and how superbly it does it. And getting new firmware is icing on the cake. > > But I sure wish I had 0-50ms amp delay capability! How about it, Wayne? > > George, N4YM > > K2 # 4758 > K3 # 340 > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by George-122
George wrote:
>The FAQ for the K3 promised a 0-50 ms amp keying delay. We got only >0-20 ms in the latest release. I don't think 20 ms is enough in my >case, based on my primitive research. Several "experts" have said mine >might need as much as 30-35 ms. My amp's relay is a 30 yr old Potter & >Brumfield open frame model with a 120vac coil. > That's correct in my experience also. In supporting the Triode Board and Tetrode Boards, I have often measured 30ms switching delays in typical older amplifiers that use 2-pole and 3-pole open-frame relays. Such amplifiers are still being used in very large numbers - and indeed they are still being manufactured. Since the K3 will be used with a wide range of unknown amplifiers, a 20ms delay is not long enough to guarantee there will be no contact arcing when the RF appears. >To make things worse, since the K3 will not switch 120vac, I must use >another relay with a 12vdc coil in the line between the K3 and the amp, >which in turn pulls in the P&B relay. This exacerbates the matter by >taking even more time, and I'm afraid to try anything for fear it will >damage the K3 and the amp. Am I wrong?? Anyone care to comment?? > That is correct. Attempting to switch 120V AC will damage the K3, and an intermediate relay will add even more delay. But we have to draw a line somewhere. At some point we have to stop blaming the transceiver manufacturer, and accept responsibility for modifying the amplifier. The modern interface standard is that the amplifier PTT input has an open-circuit (unkeyed) voltage of no more than +12-15V DC, and that the amp can be keyed by switching this input to ground with a current of a few milliamps. All modern transceivers meet that interface standard, and the K3 meets it very comfortably. Amplifiers that require high-voltage, AC or negative switching are 30 years behind the times. If the owner wishes to use the amplifier with a modern transceiver, I think it's clearly his responsibility to bring the switching interface up to date. Every design is different, but modifications are out there on the web, and none of them should take more than an evening's work. If Elecraft can move a little too, by stretching the maximum keying delay to at least 30ms, then everyone could be happy. With a little more effort, some of these slow relays can be speeded up electronically, without the trouble of changing to faster relays. The link below gives details of a circuit that can be used to speed up any RF relays operating from a +12-24V DC supply: http://tinyurl.com/6n8wjg -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek/boards _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Ian,
Your remarks are quite appropriate. My question to those "needing" 50ms delays is: "What are you doing now with your XYZ radio?" The sequencing problem for complicated VHF/UHF setups is complex. Just delaying the RF out of the transceiver is an unlikely complete solution. It almost always requires lots of external hardware and sequencing logic/delays that is specific to the harware being used. Designing and building that is part of the endeavor. I don't understand why people are so adverse to using the inhibit line provided by the K3. It will prevent hot switching. BTW people using AC relays should be aware that they will also operate just fine on DC. (115vac relays work fine on 24VDC). Once converted for DC operation, they can be "speeded up" by methods like you point to. 73 de Brian/K3KO <quote author="GM3SEK"> |
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Two points there - The first one is, it does not fail safe if the connector is unplugged for any reason. The same applies to sequencing via an external PTT source if the radio defaults to VOX on CW. Feedback is always going to be the best way as long as it can not be bypassed by mistake. What you should do is both requiring a minimum delay to occur before transmission and also use the inhibit line. The second is a most useful tip. How general is this or is it only some coils have the correct impedance/resistance ratio? Will there be any other issues? What about long term dissipation? Mike |
Re: K3 Variable amp keying delay >>not long enough!!??
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In reply to this post by George-122
No lack of communication. :) Many people were asking for some amount of
adjustability. Up to 20mS is what Wayne could do and get it out quickly. I believe he still plans to increase this but the code is going to be more involved. The item is still on the list. ------------------------- 73, Greg - AB7R Whidbey Island WA NA-065 On Fri May 9 0:18 , AD6XY - Mike sent: > >Some lack of communication between Greg and Wayne I expect regarding the >published figures. Luckily, this is a simple thing to fix one would hope. I >sent in a list of relay transit times on 2nd April. > >It was quite clear that 20mS was needed for the smaller coaxial relays like >the very commonly used CX540 and up to 50mS for the very high power relays >that you might use on a 1.5kW 6m amplifier. I was surprised to discover the >maximum delay was set to only 20mS as this is not enough; a margin is >needed. > >The CX540 is common and http://www.nts-electronic.com/cx540d.htm tells me it >takes 20mS to engage and 15mS to release. Tohotsu relays are very common. >The CX230, CZX3500, CX600, CX800, CX140 > and CX120 are often used in amateur applications (because they are cheap). >They also all specify 20mS. > >For really high power SSB electronics (Germany) do a specialist range of >relays. These specify 30mS for the HF400 series, 40mS for the HF500/1500 >series and 50mS for the HF4000 series. > > > > >wayne burdick wrote: >> >> George, >> >> Before settling on a max of 20 ms we looked at a number of amplifiers >> and got input from several "experts. If yours (or others) really need >> more than 20 ms, I can increase the delay with some additional work. >> >> Please contact me directly if you find out any more about your >> particular delay time requirements. >> >> tnx >> Wayne >> N6KR >> >> On May 8, 2008, at 5:53 PM, George wrote: >> >>> The FAQ for the K3 promised a 0-50 ms amp keying delay. We got only >>> 0-20 ms in the latest release. I don't think 20 ms is enough in my >>> case, based on my primitive research. Several "experts" have said >>> mine might need as much as 30-35 ms. My amp's relay is a 30 yr old >>> Potter & Brumfield open frame model with a 120vac coil. >> >> >> --- >> >> http://www.elecraft.com >> >> _______________________________________________ >> Elecraft mailing list >> Post to: [hidden email] >> You must be a subscriber to post to the list. >> Subscriber Info (Addr. Change, sub, unsub etc.): >> http://mailman.qth.net/mailman/listinfo/elecraft >> >> Help: http://mailman.qth.net/subscribers.htm >> Elecraft web page: http://www.elecraft.com >> >> > >-- >View this message in context: <a href="http://www.nabble.com/K3-Variable-amp-keying-delay-%">http://www.nabble.com/K3-Variable-amp-keying-delay-% >Sent from the Elecraft mailing list archive at Nabble.com. > >_______________________________________________ >Elecraft mailing list >Post to: [hidden email] >You must be a subscriber to post to the list. >Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > >Help: http://mailman.qth.net/subscribers.htm >Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: K3 Variable amp keying delay >>not long enough!!??
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In reply to this post by George-122
Surely a 21st century top of the range transceiver like the K3 shouldn't
be expected to cater for old slow amplifiers. In the case of new amplifiers the buyers need to specify they want QSK capability. The message will eventually be circulated that slow switching linears aren't wanted! I've not measured the switching time of my Acom 1000, but understand from one of the dealers it's around 4 mS. If Acom can achieve those speeds others can. 73 Dave, G4AON K3/100 #80 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Re: K3 Variable amp keying delay >>not long enough!!??
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Why is fast switching necessary? This sounds like the planned
obsolence that Microsoft and other corporations encourage. And ACOM even has provision for routing T/R switching through the amp in most of their amps. This attitude is nonsense. 73, doug Date: Fri, 09 May 2008 15:56:47 +0100 From: Dave G4AON <[hidden email]> Surely a 21st century top of the range transceiver like the K3 shouldn't be expected to cater for old slow amplifiers. In the case of new amplifiers the buyers need to specify they want QSK capability. The message will eventually be circulated that slow switching linears aren't wanted! I've not measured the switching time of my Acom 1000, but understand from one of the dealers it's around 4 mS. If Acom can achieve those speeds others can. 73 Dave, G4AON K3/100 #80 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: K3 Variable amp keying delay >>not long enough!!??
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In reply to this post by George-122
CW semi QSK and QSK. What's the point of having the feature in the
transceiver only to have to revert to manual change over when a linear is used? The Acom 1000 with operate full QSK with the K3 without a problem. 73 Dave, G4AON K3/100 #80 =========== Why is fast switching necessary? This sounds like the planned obsolence that Microsoft and other corporations encourage. And ACOM even has provision for routing T/R switching through the amp in most of their amps. This attitude is nonsense. 73, doug _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
RE: Re: K3 Variable amp keying delay >>not long enough!!??
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Guys,
I donot understand this discussion. Someone asked for a delay longer than 20ms. It's not in the formware (yet). That's it. 73, Arie PA3A _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by gm3sek
Ian White GM3SEK wrote:
> That is correct. Attempting to switch 120V AC will damage the K3, and an > intermediate relay will add even more delay. <snip> > Amplifiers that require high-voltage, AC or negative switching are 30 > years behind the times. If the owner wishes to use the amplifier with a > modern transceiver, I think it's clearly his responsibility to bring the > switching interface up to date. Every design is different, but > modifications are out there on the web, and none of them should take > more than an evening's work. I agree. One simple modification that you can make without changing the relay is to provide a 28-30 volt DC source in the amplifier. This will operate a 120 volt AC relay reliably (and may make it quieter, too). The K3's switching circuit will handle 30vdc easily. Of course, you still have to determine the delay needed. -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: K3 Variable amp keying delay >>not long enough!!??
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Administrator
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In reply to this post by George-122
Hi George!
We start to bump up against shortening the first dit on CW when delays longer than 20 mS are selected. We'd certainly like to support longer TX delays, but it will take a little head scratching and f/w work to make it happen. We'll certainly strive to do as much as we can in this area. If you and other members on the list can send me the max delay supported by other rigs currently on the market, that will help us figure out if this is reasonable. I was unaware of any commercial rig supplying much above 20-25 mS of keyout to RF delay. The K2 provides 10-12 mS of delay and we've had very few complaints even with that. What delay does the Pro-III support? Were you able to drive your amplifier in semi-break-in with it? I am unaware of any current production Ham rig that supports directly keying high current AC relays with greater than 20-25 mS long delays. (But I could be wrong :-) That's why many VHF ops, who require long delays for their transverter and antenna switch chains, usually use a foot switch to manually key everything before generating RF. One other thought, just looking at the theoretical worst case relay settling time may overstate the delay required. What is the time delay for the amp RF path itself? Also, the worst case settling delay is usually specified for DC or low freq AC loads. At RF, the contacts may be close enough, with enough contact to provide a very low impedance RF path well before this time, even if they are still settling. In any case, we'll keep looking at this. 73, Eric WA6HHQ ====== George wrote: > I don't think 20 ms is enough in my case, based on my primitive research. Several "experts" have said mine might need as much as 30-35 ms. My amp's relay is a 30 yr old Potter & Brumfield open frame model with a 120vac coil. > > To make things worse, since the K3 will not switch 120vac, I must use another relay with a 12vdc coil in the line between the K3 and the amp, which in turn pulls in the P&B relay. This exacerbates the matter by taking even more time, and I'm afraid to try anything for fear it will damage the K3 and the amp. Am I wrong?? Anyone care to comment?? > > One of the many reasons I bought the K3 was to be able to operate at least semi break in CW and VOX with my old amp without hot switching, by virtue of having ample switching delay. I've waited months for the feature and am disappointed.. > > However, I hasten to add this: As a K2 user/owner/builder, I expected much in the K3. I got much more than I expected. I gave up a nice Icom Pro 3 for the K3 and don't miss the Pro 3 one iota. The K3 is unbelievable in what it can do and how superbly it does it. And getting new firmware is icing on the cake. > > But I sure wish I had 0-50ms amp delay capability! How about it, Wayne? > > George, N4YM > > K2 # 4758 > K3 # 340 > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Greg - AB7R
Greg - AB7R wrote:
>No lack of communication. :) Many people were asking for some amount of >adjustability. Up to 20mS is what Wayne could do and get it out quickly. I >believe he still plans to increase this but the code is going to be >more involved. >The item is still on the list. Thanks, Greg - that's all we need to know for the present. When Wayne revisits this feature, a reasonable goal would be 30ms, which would accommodate the vast majority of HF amplifiers. (The FT-1000 series have the same adjustment range.) Whatever the transceiver/amplifier combination, the way to adjust the transceiver's key-down delay is to use a low level of drive, and start at the maximum delay the transceiver can provide. Progressively shorten the delay until severe clicks begin to appear at key-down, because RF is arriving before the relay contacts have fully settled. Then increase the delay to a safe value at which no clicks appear, even at full power. -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek/boards _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
K3 Variable amp keying delay >>not long enough!!??
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In reply to this post by George-122
"If you and other members on the list can send me the max delay supported
by other rigs currently on the market, that will help us figure out if this is reasonable." Hi Eric - I have looked at this (part of my effort to make a QSK mod to my ALS-600). I found the following: IC-706MKIIG: 13ms (fixed) IC-7000: 8ms (fixed) TS-480/2000: 10ms or 25ms (selectable) TenTec Orion/OmniVII: 15ms (fixed) Yaesu MKV: 5-30ms variable Yaesu FT-2000: 15ms (fixed) Phil - AD5X _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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