Re: [Elecraft] New Output Power Issue, and a new question
***Correction; make that voltage readings instead of 'ammeter readings'*** Yes, the outside insulation diameter looks the same as the K3 wire, but I can see a difference in the wire size. It was a piece I had. There are no markings. I now live rural. I can buy single 10 ga. black and red locally that I trust. I will put both in my cordless drill and twist them. I want to have a second person to operate the key when I use a DVM. Bert's K3 ammeter readings were very similar to mine, and spot-on at key up. If you followed those readings, you know what that indicates! Rich, n0ce - Original Message - From: bill ny9h To: Richard Fjeld ; n...@aol.com Cc: elecraft posting Sent: Wednesday, December 26, 2012 7:12 PM Subject: Re: [Elecraft] New Output Power Issue, and a new question I used a piece of red/black paired wire .. prompts me to mention that just because it says it is 10 gauge or 12 or whatever gauge take a good look before you buy that spool...i have bought stuff red/black that was NOT as printed on the spool or the wire. and as you might guess it was too small diameter. I keep some standards... and a wire gauge.. ( I love the hamfest vendors that label that stuff 12 guage bill __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] New Output Power Issue, and a new question
Don, thanks for your reply and your concern; No, the section of wire that I need to replace is from the PS to the distribution blocks. That section of wire now appears to be one size smaller than the K3 wire. It should be equal, or larger. The present wire length may not make much difference in resistance, but I don't want an impairment to exist. I'm CC'ing this to the group to clear up any mis-understanding. While I have the band width, Bert n4cw mentioned fuses/holders can be a source of voltage drop. He is so right. On a former job, we routinely looked for voltage drop across our large fuses during normal use. Thanks again, Rich, n0ce - Original Message - From: Don Wilhelm To: Richard Fjeld Cc: bill ny9h Sent: Thursday, December 27, 2012 10:43 AM Subject: Re: [Elecraft] New Output Power Issue, and a new question Rich, The 10 ga. wire is too large to fit into the APP connectors supplied by Elecraft. Either use 12 ga. or if the run is long, use the 10 ga. and get APP connectors that fit it. 73, Don W3FPR On 12/27/2012 10:50 AM, Richard Fjeld wrote: Yes, the outside insulation diameter looks the same as the K3 wire, but I can see a difference in the wire size. It was a piece I had. There are no markings. I now live rural. I can buy single 10 ga. black and red locally that I trust. I will put both in my cordless drill and twist them. I want to have a second person to operate the key when I use a DVM. Bert's K3 ammeter readings were very similar to mine, and spot-on at key up. If you followed those readings, you know what that indicates! Rich, n0ce __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] New Output Power Issue, and a new question
First of all, regarding a DC power distribution strip: I used a RigRuner 4009 and found that there was a significant voltage drop from the power source (Astron RS-35M) to the K3. Having taken measurements with a DVM, I concluded that the largest drop was from the distribution strip to the K3. A simple solution was to power the K3 from the larger main wire pair that fed the distribution strip. Then, to satisfy my own curiosity, I made the following meaurements today using the DVM then I took readings with the internal K3 meter: DVM measurements: 13.773 VDC at the RS-35 terminals 13.735 VDC at K3 connector in RX mode 13.599 VDC at K3 connector in TX-Tune mode (10W out) 12.860 VDC at K3 connector in TX mode (100W out) K3 meter readings: 13.6 VDC in RX mode 13.1 VDC in TX-Tune mode (10W out) 12.4 VDC in TX mode (100W out) What's interesting is that the K3 meter current indication decreases with time when I make the test in TX mode (100W out), starting at about 18.2 Amps or so, then going down, down, down to 14.something when I let up on the hand key. I kept the key down just 15 or 20 seconds, not wanting to tempt fate!!! Power output stayed at 100W throught the procedure. H I'm satisfied with those readings: everything works just fine! Bert, N4CW __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] New Output Power Issue, and a new question
Thanks, Bert (nice call) I started out to share some info with Ian, and things got interesting at my qth. Some of your measurements are similar to mine. Here are the details of what I found in case a person is interested: I used a piece of red/black paired wire from my Astron to my homebrew distribution. Without disconnecting it, I think it looks a size smaller than the wire to the K3. I also looked at the fuse holder (buss type) and the wire on it looks smaller as well. I'm going to replace both with heavier wire. As for my distribution, I use ground blocks for AC power panels and mount them in plastic outlet boxes. I solder the ends of my wires before I tighten the screws down on them. I am not opposed to bypassing the distribution blocks if need be. I checked all my manuals for schematics, and finally downloaded them. I printed out the first six pages. I can see that the 12V out jack is not part of the ammeter sensing, so the P3 current can be ignored when using the K3 ammeter. A couple replies said the current draw will vary by band. That is good to know. I wonder if you made your measurements on the 75/80 meter band as I did. I'm curious about your mention of the 18 amps tapering down to 14 amps thing. I need to do as you did and measure the voltage with my DVM at the PS, the distribution blocks, and the K3 terminals. From your readings, I can tell the voltage drop is not nearly as great as it appeared by the K3 meter. Using the K3 readings, I have 0.5 volt lower than you on key down, and that is acceptable. I should be able to correct that. And yes, as you said, 'everything works just fine'. Thanks much, Rich, n0ce - Original Message - From: n...@aol.com To: elecraft@mailman.qth.net Sent: Wednesday, December 26, 2012 11:56 AM Subject: Re: [Elecraft] New Output Power Issue, and a new question First of all, regarding a DC power distribution strip: I used a RigRuner 4009 and found that there was a significant voltage drop from the power source (Astron RS-35M) to the K3. Having taken measurements with a DVM, I concluded that the largest drop was from the distribution strip to the K3. A simple solution was to power the K3 from the larger main wire pair that fed the distribution strip. Then, to satisfy my own curiosity, I made the following meaurements today using the DVM then I took readings with the internal K3 meter: DVM measurements: 13.773 VDC at the RS-35 terminals 13.735 VDC at K3 connector in RX mode 13.599 VDC at K3 connector in TX-Tune mode (10W out) 12.860 VDC at K3 connector in TX mode (100W out) K3 meter readings: 13.6 VDC in RX mode 13.1 VDC in TX-Tune mode (10W out) 12.4 VDC in TX mode (100W out) What's interesting is that the K3 meter current indication decreases with time when I make the test in TX mode (100W out), starting at about 18.2 Amps or so, then going down, down, down to 14.something when I let up on the hand key. I kept the key down just 15 or 20 seconds, not wanting to tempt fate!!! Power output stayed at 100W throught the procedure. H I'm satisfied with those readings: everything works just fine! Bert, N4CW __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] New Output Power Issue, and a new question
I used a piece of red/black paired wire .. prompts me to mention that just because it says it is 10 gauge or 12 or whatever gauge take a good look before you buy that spool...i have bought stuff red/black that was NOT as printed on the spool or the wire. and as you might guess it was too small diameter. I keep some standards... and a wire gauge.. ( I love the hamfest vendors that label that stuff 12 guage bill __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] New Output Power Issue, and a new question
Not a problem if you buy from reputable dealers, My preferences are The Wireman and RF Parts Connection. 73, Don W3FPR On 12/26/2012 8:12 PM, bill ny9h wrote: I used a piece of red/black paired wire .. prompts me to mention that just because it says it is 10 gauge or 12 or whatever gauge take a good look before you buy that spool...i have bought stuff red/black that was NOT as printed on the spool or the wire. and as you might guess it was too small diameter. I keep some standards... and a wire gauge.. ( I love the hamfest vendors that label that stuff 12 guage __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] New Output Power Issue, and a new question
Good advice! (And a new question) I haven't followed this too closely until I saw Don mention blade-type automotive fuses. (Not to be confused with the heavier blade-type fuses.) We use a blade-type automotive fuse at our repeater site. I found the fuse holder melted one day. The fuse blade had slipped to one side of the internal terminal in the molded fuse holder. This caused a resistance connection. It is nearly impossible to tell when the fuse blades are properly inserted into the two terminals. As the current increased across the resistance the voltage drop increased. The Voltage times the current, produced enough wattage to melt the fuse holder, nearly creating a fire. Thankfully, it burned open. For Ian's benefit, I made some observations of my K3 for comparison, using my homebrew power distribution lash-up, and the wire used. (Emphasis on the latter) My Astron 35M is a bit light on voltage. Two DVMs show 13.66, and 13.72 Volts at the power supply. The K3 shows 13.6 V at the radio during key up. With key down, the K3 shows 11.9 V, and 15.4+ Amps. The Astron ammeter indicates at least 14 Amps. (I don't see the volt meter vary on the Astron) ***Considering that I have a P3 attached, Does that amperage track with other users?*** (Using simple math, the K3 seems to be very efficient on CW.) So, in summary, with my PS voltage and wiring lash-up, I am losing 1.7 Volts on key down. It indicates a full 100 Watts at the K3, at my in-line power meter to the dummy load, and also into a service monitor. All tests were done on 75 meters. Rich, n0ce P.S. Don mentioned low voltage, high current applications. Accidents can also weld firmly together in those situations. Planning good fuse placement is important. - Original Message - From: Don Wilhelm To: elecraft@mailman.qth.net Sent: Monday, December 24, 2012 6:43 PM Subject: Re: [Elecraft] New Output Power Issue Despite the potential for voltage drop, I would not forget the fuse at the power supply end of the wire unless you are certain the power source has adequate overcurrent protection built in. The blade type fuses with tight fitting sockets will cause very little voltage drop. If the connection is not in the milliohm range, connection tightness is to blame. That fuse is not intended to protect the equipment connected, but is instead to protect the wire from a short circuit. Many power supplies do have adequate overcurrent protection - however --- I hear of instances where this was not in place when the power source is a battery. In the event of a short at the end of the power cable (or internal to the cable), a LOT of energy can be available which will have current sufficient to melt copper conductors of any size and spew molten metal all over the place - a personnel and a fire hazard. Low voltage high current power sources can be just as maiming as high voltage supplies. Please be safe! Merry Christmas and Happy New Year. Keep all hams healthy and free of injury in the coming New Year. 73, Don W3FPR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
