Re: [Elecraft] OT: The day I found out I was going to be an engineer
On 9/17/2023 6:16 AM, Larry (K8UT) wrote: One of my favorite Dilbert videos - when mom discovers her son has "the knack"." I love that clip! It makes me laugh every time. (Yes, I am an engineer...) -=d -- David Thompson, AG7TX __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] KI03B equipped K3 with N1MM and MMTTY
Guessing, but the audio setting would be found in MMTTY not N1MM. Connect CODEC there and you should be good for AFSK. GL, Rick nk7i On 9/22/2023 4:53 PM, Pete Smith N4ZR wrote: For the first time in maybe 6 years I thought I'd spend a little time in the CQWW RTTY contest this weekend. I selected the contest, and to my surprise N1MM and MMTY came up and I was receiving RTTY. Alas, when I tried to transmit in AFSK, it appears that no audio is making it to the K-3. I think that this is probably because since the last time I did RTTY, I installed a KIO3B in my K-3, I'm guessing that MM wants to see the AFSK audio passed through the KIO3B's sound card, but I don't know what has to be done to get this to happen. Anyone out there with advice? I have gone into the N1MM manual but failed to find anything. __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] KI03B equipped K3 with N1MM and MMTTY
For the first time in maybe 6 years I thought I'd spend a little time in the CQWW RTTY contest this weekend. I selected the contest, and to my surprise N1MM and MMTY came up and I was receiving RTTY. Alas, when I tried to transmit in AFSK, it appears that no audio is making it to the K-3. I think that this is probably because since the last time I did RTTY, I installed a KIO3B in my K-3, I'm guessing that MM wants to see the AFSK audio passed through the KIO3B's sound card, but I don't know what has to be done to get this to happen. Anyone out there with advice? I have gone into the N1MM manual but failed to find anything. -- 73, Pete N4ZR __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] Elecraft AT1 Attenuator
Thanks to John, Joe and Mike for the feedback. Mike hit it on the head when he mentioned the slide switches. It was oxidisation and some vigorous switch gymnastics cured it. I now have readings that complement John's matrix. I know right well I should have guessed this, but I knee-jerked as usual. Cheers to all, Steve, G4VRR. e ... __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] AT1 Attenuator
2-Port VNWA measurements at 7MHz Switch, VSWR, dB 0 1.01 0.07 1 1.03 1.06 1 1.03 1.06 3 1.02 3.08 6 1.03 6.31 10 1.02 9.78 20 1.05 19.97 VSWR approaches 1.1 at 30MHz with some switch settings. John KN5L __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] AT1 Attenuator
Looking at the AT1 manual, the switches and traces are certainly not 50 Ohm transmission lines. As such, one gets all kinds of stray behavior. While you do not say at what frequency or range of frequencies you made your test, I would suspect you will see higher SWR as one goes up in frequency and that the departure from 50 + j0 will be higher on 144 MHz than on 1.8 MHz. As a general matter, one may be able to "flatten" the SWR somewhat by placing (and "tuning") shunt capacitors across the input/output BNC connectors to compensate for the inductance of the traces and switches. 73, ... Joe, W4TV On 9/22/2023 10:14 AM, Steve Gray wrote: I have purchased a second user AT1 recently, largely due to the ruinous TransAtlantic logistics costs, but also the ongoing absence of any support here in The UK. Although purely from observation of the circuit topology it seems reasonable to assume that it is not a constant impedance array of resistors, I was quite surprised to see the high SWR readings recorded after connecting a good dummy load and an antenna analyser- encroaching as it does well into double figure readings. My received wisdom being that these devices need to look into a 50 Ohms load to preserve accuracy. I have checked all the resistors and they are extraordinarily accurate leading me to believe that it has not been cooked by the/a previous owner, and confirming the quality of Elecraft dedigns. I also noted that the greater the level of attenuation, the lower the SWR is with the lowest attenuation displaying the worst result, and the highest displaying a near perfect match, but I guess that is not surprising because it is attenuating the reflected RF too. What I would like is some reassurance that such elevated SWR readings are to be expected for a nominally 50 Ohms stepped attenuator of this nature set to the lower levels of attenuation. Steve, G4VRR. e ... __ 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 Message delivered to arch...@mail-archive.com
Re: [Elecraft] AT1 Attenuator
Hi Steve, Each attenuator section is designed to present a 50 ohm input impedance when terminated in 50 ohms. Of course that will change as frequency is increased and inductive effects take greater prominence. At what frequency(ies) did you make your measurements? What were the actual SWR readings in the various attenuator section combinations? Is your signal generator a 50 ohm output impedance unit, and do you have a known good 50 ohm termination for the attenuator output port? If the resistors measure within a few percent of their nominal values, I would suspect the slide switches and/or solder joints along the path. I would also use an impedance bridge/analyzer as a check on your SWR meter. 73, Mike, K8CN __ 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 Message delivered to arch...@mail-archive.com
[Elecraft] AT1 Attenuator
I have purchased a second user AT1 recently, largely due to the ruinous TransAtlantic logistics costs, but also the ongoing absence of any support here in The UK. Although purely from observation of the circuit topology it seems reasonable to assume that it is not a constant impedance array of resistors, I was quite surprised to see the high SWR readings recorded after connecting a good dummy load and an antenna analyser- encroaching as it does well into double figure readings. My received wisdom being that these devices need to look into a 50 Ohms load to preserve accuracy. I have checked all the resistors and they are extraordinarily accurate leading me to believe that it has not been cooked by the/a previous owner, and confirming the quality of Elecraft dedigns. I also noted that the greater the level of attenuation, the lower the SWR is with the lowest attenuation displaying the worst result, and the highest displaying a near perfect match, but I guess that is not surprising because it is attenuating the reflected RF too. What I would like is some reassurance that such elevated SWR readings are to be expected for a nominally 50 Ohms stepped attenuator of this nature set to the lower levels of attenuation. Steve, G4VRR. e ... __ 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 Message delivered to arch...@mail-archive.com
