Re: [Elecraft] [K3] IF output
Brett, Those numbers are similar to what I measured on my K3. It varies by band, but before modification I was getting in the neighborhood of -6 dB with preamp on and -17 dB with preamp off. After modification I measured +4.5 dB with preamp on and -6.5 dB with preamp off (at 10 MHz). A 0603 resistor should be fine. It's not dissipating significant power. Alan N1AL On Fri, 2010-01-15 at 22:44 -0800, Brett Howard wrote: > Ok so I decided to do the IF mod as the P3 will be ordered when it comes > out and I'd like the increased sensitivity. I'm copying elecraft and K3 > support cause I wanted to ask a simple question (as well as share the > results). First my question, I didn't have any 13K ohm resistors in > 0805 size. So I put an 0603 resistor on the same pads. Will this be > ample or should I replace it with an 0805 for power rating reasons? > > I made measurements before and after the modification and collected > results which I figured I'd share. > > Signal Generator was a Rhode and Schwartz (sp?) model number unknown. > This signal generator was uncalibrated. However the spectrum analyzer I > was using was a very recently calibrated N9020A which our cal report > gave a clean bill of health and an absolute accuracy of 0.009dBm at > -50dBm. Agilent didn't specify the accuracy at -70 but it was getting > tighter as the amplitude went lower. I did not engage the preamp in the > analyzer. > > I was making my measurements at -70dBm as its a "common ham amplitude". > I injected the signal at 7.040Mhz (cause I use that w/ my XG2 a lot) @ > -70dBm. This input was verified on the spectrum analyzer at the end of > my cable to calibrate cable losses out of the system. I then measured > the output at the IF OUT port at 8.215Mhz. > > Before > PreAmp off: -88.2dBm > PreAmp on: -77.0dBm > > After > PreAmp off: -77.9dBm > PreAmp on: -66.9dBm > > Looks like there is a tad bit of loss with the PA off (7.9dB) but then > again there is 3.1dB of gain with the PA on... Hopefully this jives > with intended results. If not hopefully its a useful data point. > > Respectfully > > ~Brett (KC7OTG) __ 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] [K3] IF output
Ok so I decided to do the IF mod as the P3 will be ordered when it comes out and I'd like the increased sensitivity. I'm copying elecraft and K3 support cause I wanted to ask a simple question (as well as share the results). First my question, I didn't have any 13K ohm resistors in 0805 size. So I put an 0603 resistor on the same pads. Will this be ample or should I replace it with an 0805 for power rating reasons? I made measurements before and after the modification and collected results which I figured I'd share. Signal Generator was a Rhode and Schwartz (sp?) model number unknown. This signal generator was uncalibrated. However the spectrum analyzer I was using was a very recently calibrated N9020A which our cal report gave a clean bill of health and an absolute accuracy of 0.009dBm at -50dBm. Agilent didn't specify the accuracy at -70 but it was getting tighter as the amplitude went lower. I did not engage the preamp in the analyzer. I was making my measurements at -70dBm as its a "common ham amplitude". I injected the signal at 7.040Mhz (cause I use that w/ my XG2 a lot) @ -70dBm. This input was verified on the spectrum analyzer at the end of my cable to calibrate cable losses out of the system. I then measured the output at the IF OUT port at 8.215Mhz. Before PreAmp off: -88.2dBm PreAmp on: -77.0dBm After PreAmp off: -77.9dBm PreAmp on: -66.9dBm Looks like there is a tad bit of loss with the PA off (7.9dB) but then again there is 3.1dB of gain with the PA on... Hopefully this jives with intended results. If not hopefully its a useful data point. Respectfully ~Brett (KC7OTG) __ 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] [K3] IF output
Thanks to all, this list is great. Am 13.01.2010 15:28, schrieb Lyle Johnson: > >> I hook my TS-850 to the IF-output,... >> I set the TS-850 to USB when listening to LSB-sigs on 80m. >> Why is this the case? >> > > The K3 uses high-side injection on all bands except 6 meters. > > 73, > > Lyle KK7P > -- 73, DM4iM __ 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] [K3] IF output
Martin, If the frequency of the LO signal applied to a mixer is higher than that of the incoming signal frequency, as is the case in the K3's receiver on all bands except 6m, then a received LSB signal will appear as a USB signal at the mixer's IF output. Also a received USB signal, for example on 20m, will appear as a LSB signal at the mixer's IF output. If the frequency of the LO signal is lower than that of the received signal, e.g. on 6m in the K3 case, this "sideband inversion" does not take place. A 6m USB signal will appear as an USB signal at IF. 73, Geoff GM4ESD DM4iM" wrote on Wednesday, January 13, 2010 at 11:33 AM >I hook my TS-850 to the IF-output, it works fine. > Make sure your "panorama-radio" is not able to transmit into your K3, > e.g. use a RX-only input or modify it. > > I set the TS-850 to USB when listening to LSB-sigs on 80m. > > Why is this the case? > > Have not yet verified if that changes when listening to higher bands. > > Martin > > -- > > 73, DM4iM __ 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] [K3] IF output
> I hook my TS-850 to the IF-output,... > I set the TS-850 to USB when listening to LSB-sigs on 80m. > Why is this the case? > The K3 uses high-side injection on all bands except 6 meters. 73, Lyle KK7P __ 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] [K3] IF output
I hook my TS-850 to the IF-output, it works fine. Make sure your "panorama-radio" is not able to transmit into your K3, e.g. use a RX-only input or modify it. I set the TS-850 to USB when listening to LSB-sigs on 80m. Why is this the case? Have not yet verified if that changes when listening to higher bands. Martin -- 73, DM4iM __ 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] [K3] IF output
It's working. I tuned around and got some really loud signals even without the preamp on. So I can move forward now trying to get the LP-Pan working. Thanks everyone, Stan Rife W5EWA -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of sr...@swbell.net Sent: Tuesday, January 12, 2010 4:34 PM To: d...@w3fpr.com Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] IF output I was expecting to hear a carrier, but after I thought about it that can't be the case. With the IF connected to the Subreceiver I can tune around either side of 8215 and hear QSO's. I have to have the Preamp on by I can hear them. Would that be considered adequate? I have done the IF mod and used a 15K resistor in place of the original. I actually had a 10K & a 15K and Gary Surrency said either one of them would work. So error on the side of caution I used the 15K. Stan Rife W5EWA -Original Message- From: Don Wilhelm [mailto:w3...@embarqmail.com] Sent: Tuesday, January 12, 2010 4:27 PM To: sr...@swbell.net Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] IF output Stan, I should think you can - although you will have to be careful to listen to the correct audio channel - it would be wierd to hear the real K3 received signal in one ear and the sub receiving the IF output signal in the other. 73, Don W3FPR sr...@swbell.net wrote: > Don, can I use the SUB receiver in the K3 to do that? I have the KBPF3 in the sub receiver. > > > Stan Rife > W5EWA > > No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.136/2616 - Release Date: 01/12/10 01:35:00 __ 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 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.136/2616 - Release Date: 01/12/10 01:35:00 __ 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] [K3] IF output
You can also try borrowing an Icom Pro series (or presumably their larger radios as well), and hook the if out to the antenna input on the Pro, which will then act as a bandscope for the K3 when tuned to 8215 kHz.. I do this at P49Y (an idea from W0YK) and it works very well. 73, andy, ae6y - Original Message - From: "Alan Bloom" To: Cc: Sent: Tuesday, January 12, 2010 1:55 PM Subject: Re: [Elecraft] [K3] IF output > You should hear whatever signals the K3 is tuned to. I'm assuming you > are connected to the IF OUT jack of the KXV3 or KXV3A. > > If you haven't done the IF output mod: > http://www.elecraft.com/K3/mods/IF_Output_Buffer_Gain_Mod_Rev_A.pdf > then the signal level will be lower than at the K3 antenna connector. > But with the K3 preamp on, the difference is small. If you can clearly > hear something on the K3, then you should be able to hear it on the K2. > > Alan N1AL > > > On Tue, 2010-01-12 at 15:05 -0600, sr...@swbell.net wrote: >> I am trying to verify the output at the IF OUT jack on the back of >> the K3. I have it connected to my K2 with the VFO set for 8215.00 and I >> see >> or hear no signal at all. Shouldn't I see the output from the K3? Is the >> signal that low that I won't even get a blip on the K2 receiver? Am I >> missing something? I see no menu entry for enabling the IF output. HELP >> >> >> Stan Rife >> W5EWA > > > __ > 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] [K3] IF output
I was expecting to hear a carrier, but after I thought about it that can't be the case. With the IF connected to the Subreceiver I can tune around either side of 8215 and hear QSO's. I have to have the Preamp on by I can hear them. Would that be considered adequate? I have done the IF mod and used a 15K resistor in place of the original. I actually had a 10K & a 15K and Gary Surrency said either one of them would work. So error on the side of caution I used the 15K. Stan Rife W5EWA -Original Message- From: Don Wilhelm [mailto:w3...@embarqmail.com] Sent: Tuesday, January 12, 2010 4:27 PM To: sr...@swbell.net Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] IF output Stan, I should think you can - although you will have to be careful to listen to the correct audio channel - it would be wierd to hear the real K3 received signal in one ear and the sub receiving the IF output signal in the other. 73, Don W3FPR sr...@swbell.net wrote: > Don, can I use the SUB receiver in the K3 to do that? I have the KBPF3 in the sub receiver. > > > Stan Rife > W5EWA > > No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.136/2616 - Release Date: 01/12/10 01:35:00 __ 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] [K3] IF output
Stan, I should think you can - although you will have to be careful to listen to the correct audio channel - it would be wierd to hear the real K3 received signal in one ear and the sub receiving the IF output signal in the other. 73, Don W3FPR sr...@swbell.net wrote: > Don, can I use the SUB receiver in the K3 to do that? I have the KBPF3 in the > sub receiver. > > > Stan Rife > W5EWA > > __ 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] [K3] IF output
Burl, Some will do that, but most will not - it all depends on the exact value of the capacitors in the VFO Range Select circuit - a few pF one way or another makes a big difference. BTW, that is what setting the L30 adjustment to get the voltage at the left end of R30 is all about. Yes, the weak reception is likely due to the bandpass filters. 73, Don W3FPR bo...@mchsi.com wrote: > My K2 will tune to 8125 and I can hear the IF signal of the K3. It is weak, > but audible. I have the IF mod installed in my K3 > > AJ9Q, Burl > > __ 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] [K3] IF output
I wonder if I could do the same with my HP 3403C True RMS meter? Stan Rife W5EWA -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Sverre Holm (LA3ZA) Sent: Tuesday, January 12, 2010 4:18 PM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] IF output If you have an oscilloscope you can connect it and see the output. I have a K3 which has the modified IF with higher output. I have a 5 MHz (-3 dB) oscilloscope in my shack for monitoring. Even at 8.215 MHz it indicates up to +/- 50 mV in the 40 m band (no ATT, no PRE). In other bands it is lower, like about +/- 5mV (no ATT, no PRE) in the 80 m band. Due to the bandwidth limitation of my oscilloscope, I guess these values should be doubled or so to find the true values. srife wrote: > > I am trying to verify the output at the IF OUT jack on the back of the > K3. > - Sverre, LA3ZA K2 #2198, K3 #3391 http://www.qslnet.de/member/la3za/K2/mod.html LA3ZA Unofficial Guide to K2 modifications -- View this message in context: http://n2.nabble.com/IF-output-tp4294395p4294893.html Sent from the [K3] mailing list archive at Nabble.com. __ 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 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.136/2616 - Release Date: 01/12/10 01:35:00 __ 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] [K3] IF output
Don, can I use the SUB receiver in the K3 to do that? I have the KBPF3 in the sub receiver. Stan Rife W5EWA - Original Message - From: Don Wilhelm To: sr...@swbell.net Cc: elecraft@mailman.qth.net Sent: Tue, 12 Jan 2010 16:06:55 -0600 (CST) Subject: Re: [Elecraft] [K3] IF output Stan, The K2 cannot receive that frequency - the dial may say so, but the VFO/PLL has maxed out at about 7400 kHz (if you are tuning from 40 meters) and although the dial continues to increment, the actual frequency will not go any higher. Even if it did, the bandpass filters would probably attenuate the signal significantly. For the same reasons I doubt that you can tune downward from 30 meters and get that low. You will have to use a general coverage receiver. 73, Don W3FPR sr...@swbell.net wrote: > I am trying to verify the output at the IF OUT jack on the back of > the K3. I have it connected to my K2 with the VFO set for 8215.00 and I see > or hear no signal at all. Shouldn't I see the output from the K3? Is the > signal that low that I won't even get a blip on the K2 receiver? Am I > missing something? I see no menu entry for enabling the IF output. HELP > > > Stan Rife > W5EWA > > __ 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 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.136/2616 - Release Date: 01/12/10 01:35:00 __ 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] [K3] IF output
If you have an oscilloscope you can connect it and see the output. I have a K3 which has the modified IF with higher output. I have a 5 MHz (-3 dB) oscilloscope in my shack for monitoring. Even at 8.215 MHz it indicates up to +/- 50 mV in the 40 m band (no ATT, no PRE). In other bands it is lower, like about +/- 5mV (no ATT, no PRE) in the 80 m band. Due to the bandwidth limitation of my oscilloscope, I guess these values should be doubled or so to find the true values. srife wrote: > > I am trying to verify the output at the IF OUT jack on the back of the > K3. > - Sverre, LA3ZA K2 #2198, K3 #3391 http://www.qslnet.de/member/la3za/K2/mod.html LA3ZA Unofficial Guide to K2 modifications -- View this message in context: http://n2.nabble.com/IF-output-tp4294395p4294893.html Sent from the [K3] mailing list archive at Nabble.com. __ 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] [K3] IF output
My K2 will tune to 8125 and I can hear the IF signal of the K3. It is weak, but audible. I have the IF mod installed in my K3 AJ9Q, Burl - Original Message - From: Don Wilhelm To: sr...@swbell.net Cc: elecraft@mailman.qth.net Sent: Tue, 12 Jan 2010 16:06:55 -0600 (CST) Subject: Re: [Elecraft] [K3] IF output Stan, The K2 cannot receive that frequency - the dial may say so, but the VFO/PLL has maxed out at about 7400 kHz (if you are tuning from 40 meters) and although the dial continues to increment, the actual frequency will not go any higher. Even if it did, the bandpass filters would probably attenuate the signal significantly. For the same reasons I doubt that you can tune downward from 30 meters and get that low. You will have to use a general coverage receiver. 73, Don W3FPR sr...@swbell.net wrote: > I am trying to verify the output at the IF OUT jack on the back of > the K3. I have it connected to my K2 with the VFO set for 8215.00 and I see > or hear no signal at all. Shouldn't I see the output from the K3? Is the > signal that low that I won't even get a blip on the K2 receiver? Am I > missing something? I see no menu entry for enabling the IF output. HELP > > > Stan Rife > W5EWA > > __ 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] [K3] IF output
I thought about that and I guess that must be the case. Stan Rife W5EWA -Original Message- From: Joe Planisky [mailto:jp...@jeffnet.org] Sent: Tuesday, January 12, 2010 3:57 PM To: sr...@swbell.net Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] [K3] IF output I don't think you'll hear much of anything on a K2 at 8.215 MHz. That's well outside the 40m passband. The K2 does not have general coverage RX. 73 -- Joe KB8AP On Jan 12, 2010, at 1:05 PM, wrote: > I am trying to verify the output at the IF OUT jack on the back of > the K3. I have it connected to my K2 with the VFO set for 8215.00 > and I see > or hear no signal at all. Shouldn't I see the output from the K3? Is > the > signal that low that I won't even get a blip on the K2 receiver? Am I > missing something? I see no menu entry for enabling the IF output. > HELP > > > Stan Rife > W5EWA > > > > __ > 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 No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.725 / Virus Database: 270.14.136/2616 - Release Date: 01/12/10 01:35:00 __ 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] [K3] IF output
Stan, The K2 cannot receive that frequency - the dial may say so, but the VFO/PLL has maxed out at about 7400 kHz (if you are tuning from 40 meters) and although the dial continues to increment, the actual frequency will not go any higher. Even if it did, the bandpass filters would probably attenuate the signal significantly. For the same reasons I doubt that you can tune downward from 30 meters and get that low. You will have to use a general coverage receiver. 73, Don W3FPR sr...@swbell.net wrote: > I am trying to verify the output at the IF OUT jack on the back of > the K3. I have it connected to my K2 with the VFO set for 8215.00 and I see > or hear no signal at all. Shouldn't I see the output from the K3? Is the > signal that low that I won't even get a blip on the K2 receiver? Am I > missing something? I see no menu entry for enabling the IF output. HELP > > > Stan Rife > W5EWA > > __ 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] [K3] IF output
I don't think you'll hear much of anything on a K2 at 8.215 MHz. That's well outside the 40m passband. The K2 does not have general coverage RX. 73 -- Joe KB8AP On Jan 12, 2010, at 1:05 PM, wrote: > I am trying to verify the output at the IF OUT jack on the back of > the K3. I have it connected to my K2 with the VFO set for 8215.00 > and I see > or hear no signal at all. Shouldn't I see the output from the K3? Is > the > signal that low that I won't even get a blip on the K2 receiver? Am I > missing something? I see no menu entry for enabling the IF output. > HELP > > > Stan Rife > W5EWA > > > > __ > 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] [K3] IF output
You should hear whatever signals the K3 is tuned to. I'm assuming you are connected to the IF OUT jack of the KXV3 or KXV3A. If you haven't done the IF output mod: http://www.elecraft.com/K3/mods/IF_Output_Buffer_Gain_Mod_Rev_A.pdf then the signal level will be lower than at the K3 antenna connector. But with the K3 preamp on, the difference is small. If you can clearly hear something on the K3, then you should be able to hear it on the K2. Alan N1AL On Tue, 2010-01-12 at 15:05 -0600, sr...@swbell.net wrote: > I am trying to verify the output at the IF OUT jack on the back of > the K3. I have it connected to my K2 with the VFO set for 8215.00 and I see > or hear no signal at all. Shouldn't I see the output from the K3? Is the > signal that low that I won't even get a blip on the K2 receiver? Am I > missing something? I see no menu entry for enabling the IF output. HELP > > > Stan Rife > W5EWA __ 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] [K3] IF output
I am trying to verify the output at the IF OUT jack on the back of the K3. I have it connected to my K2 with the VFO set for 8215.00 and I see or hear no signal at all. Shouldn't I see the output from the K3? Is the signal that low that I won't even get a blip on the K2 receiver? Am I missing something? I see no menu entry for enabling the IF output. HELP Stan Rife W5EWA __ 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] K3 IF Output Buffer Mod
On 1/11/10 3:58 PM, K3RWN wrote: > I take it this mod will increase the audio level? No, it will only increase the level of the 8 MHz signal used for a panoramic adapter (or other accessory) that appears at the IF output connector. It won't affect the audio. You only need to do this if a) you have or are planning to get a panadapter like the forthcoming Elecraft P3 or the LP-Pan, and b) you want even the weakest signals to be visible on it. -- Vic, K2VCO Fresno CA http://www.qsl.net/k2vco/ __ 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] K3 IF Output Buffer Mod
I take it this mod will increase the audio level? Please excuse my ignorance on the subject. Rich #3300 __ 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] K3 IF output
Thanks for the Chipquick suggestion; will get some of that post-haste. As for the resistor, I took a look at it again. Doesn't look as bad as I thought, and after testing it again with my vom, the reading is actually 13.04k, not 13.4 as I had originally written. That's less than .05% variance in tolerance. Perhaps I will leave it for now... that is unless anyone else from the reflector cares to chime in and suggest otherwise. 73 de James K2QI On Thu, Jan 7, 2010 at 8:18 AM, David Lankshear wrote: > I build a lot of equipment and would never ever trust a damaged > component. Don't worry too much about it now, though. Get your free sample > of Chipquick and follow the instructions, INCLUDING using the supplied > liquid flux and a cotton bud you'll steal from the XYL.. All you then need > to do is melt a small blob of Chipquick over one end of the resistor and > then go to the other end with your iron, melt the solder and push the > damaged chip off the pads. Clean up with cotton buds and flux and you'll > have pads like new. Then attach the leaded resistor and hey presto, all's > comfortable and you can sleep again! > > Believe me, Chipquik is great stuff and so is the flux as it stops the > molten chipquik fro "plating" your PCB. Don't worry though, a bit of flux, > heat and a cotton bud is all you need to tidy up. I reckon a free sample of > Chipquik lasts me around a year and I use the soldering iron quite a lot. A > kind friend got me a second free sample, but I'm going to have to bite the > bullet soon and order some from the States. I wish it, and stuff like > DeoxIT Gold, was stocked by the likes of Mouser, because it's always the > cost of shipping that spoils the deal for us who don't live in the bottom 48 > HI! > > 73 Dave, G3TJP > > > __ 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] K3 IF output
Hi Dave, I'll see what I can do to borrow another receiver. Otherwise, your Softrock suggestion seems perfect. As for the chipped resistor; I seem to have taken a very small bit off the surface at one corner. It's the black material with the value etched on top of it. I guess the edge of my screwdriver chipped it off when I was attempting to hold it down. I'm surprised it chipped so easily as I did my best not to apply too much pressure. After soldering, I did test resistance however, and got a reading of 13.4 k ohms. That seems to be within a 5% amount of variance. I don't know what the tolerance range is for this part though. Should I replace this resistor with another, or use the leaded one included with the kit? Mni tnx es 73 James K2QI _ From: G3TJP [mailto:g3...@lanks.plus.com] Sent: Wednesday, January 06, 2010 8:33 PM To: k2qi@gmail.com Subject: K3 IF output I've been following your adventures re the mod to the IF output of the K3. First of all, the signal present at the IF output is at the microvolt level - pretty much a signal level that you'd expect to come from an antenna. Rather than borrow a spectrum analyser, which may be quite difficult to organise, why not borrow a receiver? A spare rx. is of immense value. If you can borrow a rx., connect its antenna input to the IF output, tune the rx to 8.215MHz and then apply your 50uV signal to the K3 and tune it in, first on the K3 and then on the borrowed Rx. You should hear it tune in on both receivers - the K3 and the loan radio, although the IF on the K3 isn't necessarily spot on 8.215MHz. You can tune the borrowed Rx across the K3's IF bandwidth, so there you have it, the borrowed receiver is an aural spectrum analyser. If you can't borrow a Rx., you could build one of the softrock software defined radio modules that's designed for the K3 IF and use that with a computer and free SDR software to listen to the K3's IF. If you were troubled by the Softrock's oscillator feedthrough, one of Jack Smith's Clifton Laboratories Z1 buffer amps would help. Hey, if you build them both, you have the structure for a panadapter using Rocky software and a high quality soundcard in your computer. I've built one and it works just fine, but I haven't yet figured out how to do point and click on the frequency display to control the K3's tuning HI! The two kits I've mentioned are cheap! One's around $15 and the other's around $25, IIRC. They will be a good intro into the world of SDR. It's generally not a good thing to chip a bit off an SMT component. Resistors are normally tiny bricks of ceramic that have a resistive coating applied on one side (usually the top). This is then whittled to the required resistance by laser action. The conductive ends are then sputtered onto the chip. The surface of the laser-cut resistive element is then epoxy coated for protection. The secret of SMT wrangling is to pin the little down using vertical pressure. My SMT pinning rig consists of a bent wire coathanger to form a base with an arch (with kinks in it) until the last bit, which points downwards. To that end, I fix a cocktail stick (they're nice because the tip doesn't usually skid on the SMT's surface, but you do get through quite a few cocktail sticks HI! The kinks are there to hold a couple of fishing weights in place to provide downward pressure. To join the stick to the mutilated coathanger, I use the insert from a choc-block connector. One screw holds onto the coathanger and the other holds onto the cocktail stick. It all boils down to having a means of applying pure vertical pressure on the component you intend attaching. For simple SMT rework involving removal of a component, Google Chipquik. Brilliant stuff if you follow the instructions. They do free samples, so if you're frugal with it, a free sample will last a long time! There you go, I hope there's something in the above that is of help to you. 73 DaveL G3TJP __ 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] K3: IF output buffer gain modification
> We just bought a new spectrum analyzer from Agilent which > with all the options we got only cost around 55,000. This unit > is an N9020A and its very accurate. Yes, that's a beautiful instrument, Brett. I guess my comments were directed toward the 1000's of older conventional analyzers out there. However, it is still instructive to temper your (Agilent's) claims for absolute accuracy a little bit. Allow me to be a real stickler for a moment: The +/- 0.23 dB spec is what Agilent calls the "95th percentile" spec, meaning that 95% of the units will probably meet it. But it is not guaranteed. Furthermore, the data sheet for that signal analyzer says that the guaranteed spec is: +/- 0.33 dB + 0.6 dB frequency response error below 10 MHz = approx. +/- 1 dB. So this is closer to the spec that I would quote someone. Note that I'm not adding in the uncertainty due to mismatch (which appears to be 1.2:1 at the instrument's input in the HF range). Note that that analyzer also calibrates itself *after every sweep* with an internal power meter! Yours may be really close to your power meter's reading, but if you didn't have that power meter to tell you that, your uncertainty would have been the figure I gave above. I loved your "only $55,000" comment. :^) Regards, Al W6LX __ 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] K3: IF output buffer gain modification
If it were within +/- 2.0dB absolute accuracy I'd be tickled pink. However your comments about spectrum analyzers today are a bit dated. Power meters are becoming much less crucial for getting accurate readings. We just bought a new spectrum analyzer from Agilent which with all the options we got only cost around 55,000. This unit is an N9020A and its very accurate. Their specification is +/- .23 dB absolute accuracy and it matches with our power meter dead nuts on. The thing even has a 35dB preamp with 10dB NF built in and it covers almost the full bandwith of the unit (100Khz to 13.6Ghz). The unit itself can measure down to 3Hz. Its not that I needed to understand what went into the calculation and while the question may have sounded ignorant I was more looking for a value than an explanation why it was worse than some may have thought I was looking for. ~BTH On Tue, 2009-09-22 at 20:40 -0700, Al Lorona wrote: > > Are there any thoughts as to the accuracy level in dBm in correlation > > with this mod? As well as any sort of absolute accuracy specs on what > > we expect to see with this box? > > The absolute accuracy will almost certainly not be better than about +/- 2.0 > dB... which is the best that spectrum analyzers from Rohde&Schwarz, Agilent, > and others could do. > > Most people are quite surprised to hear that their US$70,000 spectrum > analyzer could be off by 2.0 dB. But that is the reality. An error analysis > of a spectrum analysis measurement is well-known: frequency response, > mismatch, IF gain (reference level), and calibrator uncertainty all come into > play. The result is somewhere in the neighborhood of +/- 1.8 dB or worse. > That is considered quite good! When making a relative measurement (the > difference between two signals) it's even worse. For more information and > specific examples, see > http://cp.literature.agilent.com/litweb/pdf/5968-3659E.pdf . > > The main thing to remember is that a panadaptor display is good, but it's not > absolutely accurate in power. If you need excellent power accuracy, you must > use a power meter. > > There are a lot of stages before the P3 panadaptor that conspire to increase > the measurement uncertainty. Consider that before the signal even reaches the > receiver it has already undergone the loss in the transmission line and the > connectors. Do you know exactly how much loss you have in your transmission > line and connectors? Following this, the signal then hits the receiver input > which is not exactly 50 ohms. It could be 20. Or 90. Because it's not exactly > 50, there is mismatch uncertainty. Already two errors right there. > > On the inside of the rx, there are a number of switches, cables, and bandpass > filters (with amplitude ripple), then an attenuator and RF amp, mixer, and > post-mixer amp. Take the attenuator for example. It might claim that its > loss is -10 dB, but that's a nominal value that will actually be different > for every K3. Each of the stages mentioned has an uncertainty in its gain, > loss, or match which must be added to the total uncertainty. > > So these are all of the errors that add up to the figure I quoted at the > outset. You might have better accuracy that this, but the point is you won't > know if you do, so you must assume the worst case. > > Al W6LX > > __ > 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
[Elecraft] K3: IF output buffer gain modification
> Are there any thoughts as to the accuracy level in dBm in correlation > with this mod? As well as any sort of absolute accuracy specs on what > we expect to see with this box? The absolute accuracy will almost certainly not be better than about +/- 2.0 dB... which is the best that spectrum analyzers from Rohde&Schwarz, Agilent, and others could do. Most people are quite surprised to hear that their US$70,000 spectrum analyzer could be off by 2.0 dB. But that is the reality. An error analysis of a spectrum analysis measurement is well-known: frequency response, mismatch, IF gain (reference level), and calibrator uncertainty all come into play. The result is somewhere in the neighborhood of +/- 1.8 dB or worse. That is considered quite good! When making a relative measurement (the difference between two signals) it's even worse. For more information and specific examples, see http://cp.literature.agilent.com/litweb/pdf/5968-3659E.pdf . The main thing to remember is that a panadaptor display is good, but it's not absolutely accurate in power. If you need excellent power accuracy, you must use a power meter. There are a lot of stages before the P3 panadaptor that conspire to increase the measurement uncertainty. Consider that before the signal even reaches the receiver it has already undergone the loss in the transmission line and the connectors. Do you know exactly how much loss you have in your transmission line and connectors? Following this, the signal then hits the receiver input which is not exactly 50 ohms. It could be 20. Or 90. Because it's not exactly 50, there is mismatch uncertainty. Already two errors right there. On the inside of the rx, there are a number of switches, cables, and bandpass filters (with amplitude ripple), then an attenuator and RF amp, mixer, and post-mixer amp. Take the attenuator for example. It might claim that its loss is -10 dB, but that's a nominal value that will actually be different for every K3. Each of the stages mentioned has an uncertainty in its gain, loss, or match which must be added to the total uncertainty. So these are all of the errors that add up to the figure I quoted at the outset. You might have better accuracy that this, but the point is you won't know if you do, so you must assume the worst case. Al W6LX __ 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] K3: IF output buffer gain modification
Are there any thoughts as to the accuracy level in dBm in correlation with this mod? As well as any sort of absolute accuracy specs on what we expect to see with this box? On Tue, 2009-09-22 at 16:58 -0700, Alan Bloom wrote: > On Tue, 2009-09-22 at 19:08 -0400, amstel78 wrote: > > > So would it be advisable to wait for the P3 to come out before > > performing this modification? If it's not really needed, then what's > > the point? My antenna system isn't that great anyway... > > I need to do some more experimenting to get a better handle on this, but > I think it just depends on conditions. With the K3 preamp off on a > quiet band (e.g. VHF) you definitely want the mod. On 80 meters in the > summertime it's not necessary. If you don't do the mod you might need > to use the preamp more often than you otherwise would. > > There's no reason not to do the modification other than the hassle > factor. The P3 automatically bypasses its own preamplifier if the > signal starts to over-range. > > Alan N1AL > > > __ > 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] K3: IF output buffer gain modification
On Tue, 2009-09-22 at 19:08 -0400, amstel78 wrote: > So would it be advisable to wait for the P3 to come out before > performing this modification? If it's not really needed, then what's > the point? My antenna system isn't that great anyway... I need to do some more experimenting to get a better handle on this, but I think it just depends on conditions. With the K3 preamp off on a quiet band (e.g. VHF) you definitely want the mod. On 80 meters in the summertime it's not necessary. If you don't do the mod you might need to use the preamp more often than you otherwise would. There's no reason not to do the modification other than the hassle factor. The P3 automatically bypasses its own preamplifier if the signal starts to over-range. Alan N1AL __ 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] K3: IF output buffer gain modification
hi, fellow elecrafters, if you should have a problem with the 13 kOhm resistor, take two. 47k in parallel with an 18kOhm resistor, both SMD, solded together as piggyback onto the solderpads. It fits great. 73 from Germany Hans, DF5SR __ 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] K3: IF output buffer gain modification
On Tue, 2009-09-22 at 08:22 +0100, Ian White GM3SEK wrote: > (Also a query about the resistor value: does it truly have to be 13K? > Is this potential divider so critical that it cannot use one of the > readily available standard values of 15K, 12K or even 10K?) No, the exact value is not critical. Alan N1AL __ 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] K3: IF output buffer gain modification
Dave G4AON wrote: > >Bill W4ZV wrote: > >>When the mod was first published I asked: >>"Just checking to see if this is a typo. 13K or 12K?" >> >>Bob Friess N6CM (the 1st mixer designer) replied: >>"13K is a standard 5% value and is correct." >> >>I took the 5% tolerance to mean the value is somewhat critical. >> >There is about 0.2 dB difference between using one value or the other, >depending on the accuracy of your model. > 13K is a standard value in the E24 series, which covers a full decade in 24 steps. Each step is about 10% above the previous value, so E24 resistors have to be manufactured with a tolerance of 5% or better. http://www.logwell.com/tech/components/resistor_values.html But *standard* values aren't the same as the most-used *common* values. The ones most used are the well known E6 series (1.0, 1.5, 2.2 etc) or the E12 series (1.0, 1.2, 1.5, 1.8, 2.2 etc). Most RF circuits don't operate within 5% margins, so they can get along fine with E6 and E12 values. -- 73 from Ian GM3SEK http://www.ifwtech.co.uk/g3sek __ 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] K3: IF output buffer gain modification
13k is a standard value in the progression of 5% resistors (10, 11, 12, 13, 15, 18, 20, etc.). It is difficult to get 10% resistors anymore, and 5% tolerance is normally used. If your local parts source does not have them, perhaps they are only stocking those values from the list of 10% tolerance values to save shelf space. 73, Don W3FPR Ian White GM3SEK wrote: > (Also a query about the resistor value: does it truly have to be 13K? > Is this potential divider so critical that it cannot use one of the > readily available standard values of 15K, 12K or even 10K?) > > > __ 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] K3: IF output buffer gain modification
There is about 0.2 dB difference between using one value or the other, depending on the accuracy of your model. 73 Dave, G4AON K3/100 #80 -- Bill W4ZV wrote: When the mod was first published I asked: "Just checking to see if this is a typo. 13K or 12K?" Bob Friess N6CM (the 1st mixer designer) replied: "13K is a standard 5% value and is correct." I took the 5% tolerance to mean the value is somewhat critical. __ 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] K3: IF output buffer gain modification
On Tue, 2009-09-22 at 03:50 -0700, Bill W4ZV wrote: > > When the mod was first published I asked: > "Just checking to see if this is a typo. 13K or 12K?" > > Bob Friess N6CM (the 1st mixer designer) replied: > "13K is a standard 5% value and is correct." 13k is not standard in the bag of SMT resistors I have here ;-) so in the 3 K3's I have carried this mod out in so far I used 1K and 12k in series. SMT allows this to be done relatively neatly by standing off each resistor at approximately 45 degrees from the pad, touching in the middle. then solder Takes a bit of fiddling around but it can be done -- 73 Brendan EI6IZ __ 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] K3: IF output buffer gain modification
James Sarte wrote: > I've already done most of the > hardware mods, but SMD stuff I refuse to deal with. I too was extremely nervous about those little smd parts but I eventually plucked up courage and found it astonishingly easy. You just need plenty of light, a fine bit, tweezers and a magnifying glass to check the work. 73, Pete G4PLZ/F5VNB __ 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] K3: IF output buffer gain modification
Ian White GM3SEK wrote: > > (Also a query about the resistor value: does it truly have to be 13K? > Is this potential divider so critical that it cannot use one of the > readily available standard values of 15K, 12K or even 10K?) > When the mod was first published I asked: "Just checking to see if this is a typo. 13K or 12K?" Bob Friess N6CM (the 1st mixer designer) replied: "13K is a standard 5% value and is correct." I took the 5% tolerance to mean the value is somewhat critical. 73, Bill -- View this message in context: http://n2.nabble.com/K3-IF-output-buffer-gain-modification-tp3690284p3691931.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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] K3: IF output buffer gain modification
K2QI wrote: > > 2.If I do decide to buy the panadaptor, can Elecraft perform this > modification for me if I send the radio back? I've already done most of > the > hardware mods, but SMD stuff I refuse to deal with. > > I entirely understand your concern, but having plucked up the courage to do a couple of mods a few months ago I found it really wasn't difficult. Getting an SMT part off is a lot easier than removing through hole parts (believe me, I have the messy looking KSB2 with lifted circuit traces in my K2 to show for it.) I used two soldering irons, one at each end, and the resistor was off in a jiffy. I haven't looked at this particular mod yet since I don't have a need for it but I assume, as with the other mod, that the replacement resistor can be a leaded one if you find that easier. - Julian, G4ILO. K2 #392 K3 #222. * G4ILO's Shack - http://www.g4ilo.com * KComm - http://www.g4ilo.com/kcomm.html * KTune - http://www.g4ilo.com/ktune.html -- View this message in context: http://n2.nabble.com/K3-IF-output-buffer-gain-modification-tp3690284p3691324.html Sent from the Elecraft mailing list archive at Nabble.com. __ 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] K3: IF output buffer gain modification
I find removing surface mount resistors, at least on the underside of the K3 main board, quite simple. It's easier than removing wire ended resistors from plated through holes! Remove the bulk of the solder from each end of the component with solder wick, the heat from the iron will often have migrated through the component by this time and it will slide away from the pads, if not dab the other end. I really do not like cutting surface mount resistors and capacitors with side cutters as a means of removing them. Getting the replacement component nice and square on the board is harder than removing the old one as the heat from soldering the second end can be enough to cause the component to shift slightly. 73 Dave, G4AON K3/100 #80 with all the published mods. Ian GM3SEK wrote: >/It's an easy mod. Just remove one surface-mount resistor (cut it in />/half with side cutters / That is a very risky technique - cutters apply a very large and uncontrolled force which can easily tear up the solder pads. __ 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] K3: IF output buffer gain modification
Alan Bloom wrote: >It's an easy mod. Just remove one surface-mount resistor (cut it in >half with side cutters That is a very risky technique - cutters apply a very large and uncontrolled force which can easily tear up the solder pads. It is much safer to melt the solder at both ends of the resistor, swapping quickly between one end and the other, until the resistor gently slides off. (Also a query about the resistor value: does it truly have to be 13K? Is this potential divider so critical that it cannot use one of the readily available standard values of 15K, 12K or even 10K?) -- 73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB) http://www.ifwtech.co.uk/g3sek __ 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] K3: IF output buffer gain modification
On Mon, 2009-09-21 at 22:15 -0400, James Sarte wrote: > I've just gone through the last 800 or so recent reflector messages (I > haven't downloaded my email in a few days), and not a single one was devoted > to this hardware modification. I have a couple of questions: > > > > 1.What is this mod for? I'm assuming it's for the Elecraft panadaptor, > but why do we need to mod the K3? Couldn't the IF output be amplified by > the panadaptor? It's a noise figure issue. Amplifying the IF output can only do so much to improve the NF. (At some point you're just amplifying the noise.) That said, the P3 should work pretty well even without the IF out mod to the K3. Normal band noise is high enough that in most cases you should be able to see pretty much anything you can hear. > I'm not really comfortable cutting stuff out of my 4 > thousand dollar investment. It's an easy mod. Just remove one surface-mount resistor (cut it in half with side cutters and then clean the pads with a soldering iron) and solder in either a replacement SMT part or a leaded part using a handy nearby via hole in the PC board. Details are at: http://www.elecraft.com/K3/k3_app_notes.htm Alan N1AL __ 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] K3: IF output buffer gain modification
> 1.What is this mod for? I'm assuming it's for the Elecraft panadaptor, > but why do we need to mod the K3? Couldn't the IF output be amplified by > the panadaptor? I'm not really comfortable cutting stuff out of my 4 > thousand dollar investment. > In some circumstance, the IF output level is weaker than the signal at the antenna connector, so the S/N suffers. This mod adds gain back in the appropriate location so the attached panadaptor will be able to display signals as weak as you can hear on the K3 itself. 73, Lyle KK7P __ 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] K3: IF output buffer gain modification
I've just gone through the last 800 or so recent reflector messages (I haven't downloaded my email in a few days), and not a single one was devoted to this hardware modification. I have a couple of questions: 1. What is this mod for? I'm assuming it's for the Elecraft panadaptor, but why do we need to mod the K3? Couldn't the IF output be amplified by the panadaptor? I'm not really comfortable cutting stuff out of my 4 thousand dollar investment. 2. If I do decide to buy the panadaptor, can Elecraft perform this modification for me if I send the radio back? I've already done most of the hardware mods, but SMD stuff I refuse to deal with. 73 de James K2QI __ 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] K3 IF Output Buffer Gain Mod
Hello Eric, Since I plan to purchase and connect my K3s to the P3, I would like to make the R8 resistor value change ahead of time. Please tell me which board this resistor is on, and let me know if this mod will be posted in K3 Resources and if the resistor will be made available to purchase through Elecraft. I assume this is an SMD resistor. Thanks for firmware v. 3.27. Noise Reduction has definitely improved. Thank you for the continued improvements. I wonder if you ever sleep. Thanks. Roy Morris W4WFB __ 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] [K3] IF output
Mike, Do you have a known good receiver that will tune 8.215 MHz? If so, use it to listen to the K3 IF output. If you hear signals on that receiver as you tune the K3, then the K3 IF output is working. You said the Softrock was *not* working. The Softrock will have to work before you can use its output to drive the soundcard line-in. 73, Don W3FPR Mike Short wrote: > Is the IF output on all the time? I have a softrock that isn't > working, and was wondering if I was even getting an output. > > I built the softrock, and have Jack Smith's Buffer Amp, feeding to an > EMU-0202 USB sound card. Rocky and PowerSDR-IF do not appear to > display anything but > noise, but then I am not really sure what I am doing here. Any help > would be great. > > Mike > > ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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] [K3] IF output
Is the IF output on all the time? I have a softrock that isn't working, and was wondering if I was even getting an output. I built the softrock, and have Jack Smith's Buffer Amp, feeding to an EMU-0202 USB sound card. Rocky and PowerSDR-IF do not appear to display anything but noise, but then I am not really sure what I am doing here. Any help would be great. Mike Mike Short AI4NS ai...@arrl.net ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
