[K2] Loose screws on KPA100 Q1 and Q2
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A reminder to new KPA100 builders ... the very last step in the KPA100 construction manual is on page 55 and reminds the builder to go back and tighten the screws that hold down Q1 and Q2 after 5 hours of normal use.
I just opened up my K2/100, following the ARRL DX contest, and sure enough ... all 4 screws were loose and required the suggested 1/8 turn. And, as long as I have the top off, I'm seeing if can route the ribbon cable more optimally, and will tweak the filter alignment. Cheers - Bruce
Bruce Rosen
K1FFX K2/100 6982 KSB2 KAT100-1 KAF2 KIO2 |
Re: [K2] Loose screws on KPA100 Q1 and Q2
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It's also a good idea to re-tighten to screws periodically but not to over tighten them.
Ken..G0ORH Sent from my iPhone Member of:- RSGB, NADARS, CDXC, FOC 1684, G-QRP 13178, IPA. On 1 Mar 2011, at 22:29, K1FFX <[hidden email]> wrote: > A reminder to new KPA100 builders ... the very last step in the KPA100 > construction manual is on page 55 and reminds the builder to go back and > tighten the screws that hold down Q1 and Q2 after 5 hours of normal use. > > I just opened up my K2/100, following the ARRL DX contest, and sure enough > ... all 4 screws were loose and required the suggested 1/8 turn. > > And, as long as I have the top off, I'm seeing if can route the ribbon cable > more optimally, and will tweak the filter alignment. > > Cheers - > > Bruce > > > > ----- > Bruce Rosen > K1FFX > k2/100 6982 > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/K2-Loose-screws-on-KPA100-Q1-and-Q2-tp6078966p6078966.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:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: [K2] Loose screws on KPA100 Q1 and Q2
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In reply to this post by K1FFX
Bruce,
Yes that is a good reminder - also note that it should be re-done if you change the thermal pads. For anyone who has had a KPA100 built for them, it might be a bit intimidating at first to get to the screws. For anyone in that position, send me an email, and I will send you the document that I normally send to customers for whom I build a KPA100 or change the thermal pads. Route the ribbon cable (and the speaker cable) toward the front. It should exit the shield running straight out. If it does not fit that way, swap ends. When the KPA100 is mounted onto the base K2, tuck the ribbon cable and the speaker cable up into the space above the Control Board and as far away from the KSB2 as possible and reasonable. 73, Don W3FPR On 3/1/2011 5:29 PM, K1FFX wrote: > A reminder to new KPA100 builders ... the very last step in the KPA100 > construction manual is on page 55 and reminds the builder to go back and > tighten the screws that hold down Q1 and Q2 after 5 hours of normal use. > > I just opened up my K2/100, following the ARRL DX contest, and sure enough > ... all 4 screws were loose and required the suggested 1/8 turn. > > And, as long as I have the top off, I'm seeing if can route the ribbon cable > more optimally, and will tweak the filter alignment. > > Cheers - > > Bruce > > > > ----- > Bruce Rosen > K1FFX > k2/100 6982 > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: [K2] Loose screws on KPA100 Q1 and Q2
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In reply to this post by Ken Chandler
Ken,
While that is a good idea, I have never found it to be necessary. I check on all the K2/100s that I repair. Once the pads have "settled in", they do not compress any further. 73, Don W3FPR On 3/1/2011 5:43 PM, Ken Chandler wrote: > It's also a good idea to re-tighten to screws periodically but not to over tighten them. > > Ken..G0ORH > > Sent from my iPhone > Member of:- > RSGB, NADARS, CDXC, FOC 1684, G-QRP 13178, IPA. > > > > > On 1 Mar 2011, at 22:29, K1FFX<[hidden email]> wrote: > >> A reminder to new KPA100 builders ... the very last step in the KPA100 >> construction manual is on page 55 and reminds the builder to go back and >> tighten the screws that hold down Q1 and Q2 after 5 hours of normal use. >> >> I just opened up my K2/100, following the ARRL DX contest, and sure enough >> ... all 4 screws were loose and required the suggested 1/8 turn. >> >> And, as long as I have the top off, I'm seeing if can route the ribbon cable >> more optimally, and will tweak the filter alignment. >> >> Cheers - >> >> Bruce >> >> >> >> ----- >> Bruce Rosen >> K1FFX >> k2/100 6982 >> >> -- >> View this message in context: http://elecraft.365791.n2.nabble.com/K2-Loose-screws-on-KPA100-Q1-and-Q2-tp6078966p6078966.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:[hidden email] >> >> 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:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Don Wilhelm-4
> Route the ribbon cable (and the speaker cable) toward the front. It
> should exit the shield running straight out. If it does not fit that > way, swap ends. Swap ends! What a concept! Of course, that made a huge difference in routing the cable directly and _easily_ straight toward the front. I've been fighting with that ribbon cable from day 1 ... thanks for the helpful observation and tip, Don. - Bruce
Bruce Rosen
K1FFX K2/100 6982 KSB2 KAT100-1 KAF2 KIO2 |
Re: [Bulk] [K2] Loose screws on KPA100 Q1 and Q2
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In reply to this post by K1FFX
On Mar 1, 2011, at 5:29 PM, K1FFX wrote: > A reminder to new KPA100 builders ... the very last step in the KPA100 > construction manual is on page 55 and reminds the builder to go back and > tighten the screws that hold down Q1 and Q2 after 5 hours of normal use. > > I just opened up my K2/100, following the ARRL DX contest, and sure enough > ... all 4 screws were loose and required the suggested 1/8 turn. Every time I have the K2 open, and the KPA100 shield off, I check this. I've only found them loose the first time, and I've had the KPA100 board off the heat sink a couple of times. > And, as long as I have the top off, I'm seeing if can route the ribbon cable > more optimally, and will tweak the filter alignment. Ribbon cable position makes a difference, I found. However, once set, the filters seem to stay put. Here's my tips on setting up and aligning the filters: http://boringhamradiopart.blogspot.com/2010/02/configuring-elecraft-k2-crystal-filters.html Bill Coleman, AA4LR, PP-ASEL Mail: [hidden email] Web: http://boringhamradiopart.blogspot.com Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: [Bulk] [K2] Loose screws on KPA100 Q1 and Q2
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Bill,
Good information on your blog. For additional information on setting the K2 filters and the dial calibration, I refer you to the K2 Dial Calibration article on my website. Yes, once set the K2 filters will stay put. There is no need for continual filter changes unless the K2 owner is simply experimenting to see what works best for him/her. See the K2 Dial Calibration article on my website www.w3fpr.com for more information on how to accomplish the optimum filter settings for your K2. My recommended RTTY filter set settings are - FL1 = The same as the SSB FL1 settings - that gives you the full waterfall display - FL2 = 1.00, FL3 = 0.70, and FL4 = 0.40. Those narrow filters are centered at 1000 Hz (change the KDSP2 RTTY filter centers to match), and set the MMTTY mark frequency to 910 Hz. When tuning PSK31 signals in the midst of QRM, use the VFO knob to tune the desired signal to the vicinity of 1000 Hz on the waterfall, and then if you need to narrow the IF filters to alleviate QRM, it is a simple matter of tapping the XFIL button. Note that there may be a slight difference in the BFO frequency (up to 20 Hz) when switching IF filter widths. To maintain a QSO and keep the QSO on the same frequency, unlock the transmit and receive frequencies in the data mode application when using these techniques, and you will avoid chasing the QSO frequency up or down the band. 73, Don W3FPR On 3/1/2011 9:01 PM, Bill Coleman wrote: > > Ribbon cable position makes a difference, I found. However, once set, the filters seem to stay put. Here's my tips on setting up and aligning the filters: > http://boringhamradiopart.blogspot.com/2010/02/configuring-elecraft-k2-crystal-filters.html > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: [Bulk] Re: [Bulk] [K2] Loose screws on KPA100 Q1 and Q2
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On Mar 1, 2011, at 9:30 PM, Don Wilhelm wrote: > My recommended RTTY filter set settings are - FL1 = The same as the SSB FL1 settings - that gives you the full waterfall display - FL2 = 1.00, FL3 = 0.70, and FL4 = 0.40. Those narrow filters are centered at 1000 Hz (change the KDSP2 RTTY filter centers to match), and set the MMTTY mark frequency to 910 Hz. When tuning PSK31 signals in the midst of QRM, use the VFO knob to tune the desired signal to the vicinity of 1000 Hz on the waterfall, and then if you need to narrow the IF filters to alleviate QRM, it is a simple matter of tapping the XFIL button. Don, As much as I hate to contradict your expertise -- are you sure it is wise to use such a low center frequency for AFSK RTTY? (Although it does more easily fit the limited BFO range of the standard K2) Part of the reason RTTY tones are traditionally so high (2125/2295) is to put any harmonics or other distortion products outside the audio passband. With tones centered around 1000 Hz, the second harmonic, and much of the energy of the third harmonic is well within the standard SSB passband. Also, if tones are centered around 1000 Hz, then the mark frequency would be 915 Hz (1000 - 170/2), and the space frequency 1085 Hz. I chose 1500 Hz as a center frequency since it put the harmonics outside the audio passband. (I use a rather narrow SSB filter - about 2 kHz wide) A center frequency on 100 Hz boundaries allows KDSP2 filters to be properly centered. I did have to make a minor modification to give the BFO enough range to allow the crystal filter to be set at this point. Bill Coleman, AA4LR, PP-ASEL Mail: [hidden email] Web: http://boringhamradiopart.blogspot.com Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: [Bulk] Re: [Bulk] [K2] Loose screws on KPA100 Q1 and Q2
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Bill,
It is a matter of practical consideration. Most K2 BFO ranges will support a LSB filter width of 400 Hz centered at 1000 Hz. but not much more, although some have to be padded a bit to obtain that sufficient range. The USB filter is typically no problem, but RTTY is usually LSB. Narrow filters are usually more important for RTTY than they are for other data modes. Yes, you are correct, images could be a problem if the transmit audio is overdriving the KSB2, but then I look at that problem as an operator consideration, and can be corrected easily - the K2 operates in a linear mode if it is not overdriven. MMTTY conveniently provides for a mark frequency of 910 Hz. That is the one to use with the K2. 73, Don W3FPR On 3/2/2011 8:06 AM, Bill Coleman wrote: > On Mar 1, 2011, at 9:30 PM, Don Wilhelm wrote: > >> My recommended RTTY filter set settings are - FL1 = The same as the SSB FL1 settings - that gives you the full waterfall display - FL2 = 1.00, FL3 = 0.70, and FL4 = 0.40. Those narrow filters are centered at 1000 Hz (change the KDSP2 RTTY filter centers to match), and set the MMTTY mark frequency to 910 Hz. When tuning PSK31 signals in the midst of QRM, use the VFO knob to tune the desired signal to the vicinity of 1000 Hz on the waterfall, and then if you need to narrow the IF filters to alleviate QRM, it is a simple matter of tapping the XFIL button. > Don, > > As much as I hate to contradict your expertise -- are you sure it is wise to use such a low center frequency for AFSK RTTY? (Although it does more easily fit the limited BFO range of the standard K2) > > Part of the reason RTTY tones are traditionally so high (2125/2295) is to put any harmonics or other distortion products outside the audio passband. With tones centered around 1000 Hz, the second harmonic, and much of the energy of the third harmonic is well within the standard SSB passband. > > Also, if tones are centered around 1000 Hz, then the mark frequency would be 915 Hz (1000 - 170/2), and the space frequency 1085 Hz. > > I chose 1500 Hz as a center frequency since it put the harmonics outside the audio passband. (I use a rather narrow SSB filter - about 2 kHz wide) A center frequency on 100 Hz boundaries allows KDSP2 filters to be properly centered. I did have to make a minor modification to give the BFO enough range to allow the crystal filter to be set at this point. > > Bill Coleman, AA4LR, PP-ASEL Mail: [hidden email] > Web: http://boringhamradiopart.blogspot.com > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: [Bulk] Re: [Bulk] [K2] Loose screws on KPA100 Q1 and Q2
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In reply to this post by Bill Coleman-2
On 3/2/2011 5:06 AM, Bill Coleman wrote:
> s much as I hate to contradict your expertise -- are you sure it is wise to use such a low center frequency for AFSK RTTY? (Although it does more easily fit the limited BFO range of the standard K2) Many good RTTY operators use 915 Hz as the mark frequency because it's much easier to listen to. Distortion should be low if you are using a proper interface and adjusting audio levels properly. With the K2, that means an interface that includes a simple 20 dB attenuator (resistive voltage divider) between the sound card output and the mic input. The sound card output level should be set at least 6dB below its max output voltage, and the K2 mic gain should be set just below the point where output power starts to level off. To set the sound card output level with a scope, look at the waveform at the output of the sound card while sending tones from the RTTY program, increase level until you just begin to see clipping, then reduce the voltage by one half. If you don't have a scope, LISTEN carefully to the tones as you increase the level. At some point, the SOUND of the tones will get "brighter" or "harsh." That's clipping. Now, back off the level until it sounds "half as loud." That's where you want to run the sound card. This setup procedure works for ANY rig and ANY sound card, not only the K2. 73, Jim Brown K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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