KSYN3A FAQ
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In response to a gazillion questions:
* * * Q: What is involved in upgrading from the KSYN3 to the KSYN3A? A: The KSYN3A plugs into the same connectors as the KSYN3s for the main and sub synthesizers. There are minor differences in cable routing that are covered in the accompanying installation instructions. No user calibration is required for the KSYN3A, simplifying the installation process. Version 5.10 or later K3 firmware is required (presently available on our web site as a beta release). Q: Will the new synthesizer module be included in future orders of the KRX3 sub receiver? A: Yes. But we also have limited quantities of the original synthesizer boards for those with existing K3s who wish to add a KRX3 but not upgrade the synth. Questions on specific orders should go to [hidden email]. Q: What is the approximate 2-kHz dynamic range (IMDDR3) of the K3 when using the new synthesizer? A: Our tests show in excess of 105 dB with the narrowest filters, though there are many factors, and this should be considered approximate. (A very robust test setup is required to make these measurements.) A third party has obtained similar results, but they have not published them yet. When they do, we will update this FAQ. Q: How much lower is the KSYN3A's phase noise than that of the original KSYN3? How does this affect signals? A: At an offset of 2 kHz, the KSYN3A's phase noise is typically 15 to 20 dB lower on a given band. Generally speaking, this means a smaller increase in the noise floor in receive mode in the presence of very strong close-in signals. The limiting factor would then be how clean everyone else's signals are. Your own transmit signal will be cleaner when using the KSYN3A, though the K3 already has one of the cleanest transmitters available, accounting for its popularity with DXpeditions and multi-transmitter contest stations. Q: What is the K3's 100-490 kHz receive sensitivity? What signals would I find in this range? A: With preamp OFF, we measured about -125 dBm at 475 kHz and -90 dBm at 250 kHz. We have not measured MDS below 250 kHz, but the receiver will gradually become less sensitive as you go lower in frequency due to band-pass filter rolloff (in the KBPF3, which is required for operation below 160 meters). These tests were made with the signal routed through the RX ANT IN or XVTR IN jacks on the KXV3 option module. The preamp is not effective in this range and must be turned off. A sub receiver (KRX3) fitted with a KBPF3 should have similar performance, whether the signal is obtained from the main path (KXV3) or from the sub's AUX RF input. As for signals: there's the 600-meter band (more on that below), a large number of commercial CW beacons (for example, see www.dxinfocentre.com/ndb.htm), and other interesting phenomena. We've just begun to explore it ourselves! Q: Will I notice any change in performance if I upgrade to the KSYN3A? A: First there's the obvious -- the ability to tune the VFOs much lower in frequency. If you're a high-speed CW operator, you should be able to hear an improvement in CW element timing at high code speeds, as well as somewhat faster receive recovery. The dynamic range of the K3 was already excellent, and its phase noise very low, so you might notice the additional improvement in these parameters only in very difficult signal conditions. Q: How does the new synth affect CW operation? A: The KSYN3A switches faster than the KSYN3, which allows us to more precisely control CW timing. This means less "jitter" (timing variation) at high CW speeds. Many CW operators who had been using "QRQ" mode (CONFIG:CW QRQ=ON) for CW in the 35-60 WPM range will now be able to use normal CW mode (CW QRQ=OFF), meaning they no longer give up RIT and SPLIT when using fast CW. Receive recover times also improve. Note that we recently introduced a variation on CW break-in signal processing called "NEW QSK" (selected by tapping '3' in the CW WGHT menu entry). This eliminates audio T/R artifacts heard with the original algorithm ("OLD QSK"), at the expense of some slowing of receive recovery (by purging the DSP's "pipeline"). Installing a KSYN3A speeds up receive recovery for both the OLD and NEW QSK settings. Q: What is required to use the 600-meter band? A: This band is available in some countries, often on an experimental basis. Specific restrictions may apply. A K3 fitted with a KSYN3A, as well as a KXV3 and KBPF3, can receive signals on this band, and can put out about 1 milliwatt of transmit power. An external amplifier will be needed, connected to the XVTR OUT jack. At present we don't have information on such amplifiers. You can also get on this band using an up-conversion transverter whose output is on a low HF band (also not presently supplied by Elecraft). For a general introduction to the 600-meter band, see: wikipedia.org/wiki/600-meter_amateur_radio_band Q: Can a transverter I.F. of "0" be defined as an alternative to setting CONFIG:KXV3 to TEST? A: Not at this time, though we hope to add this capability. Those who frequently alternate between TEST and NOR modes can assign the KXV3 menu entry to a programmable function switch, or write a switch macro to change this menu setting as well as set up the VFO, preamp, etc., for this band. ______________________________________________________________ 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 Message delivered to [hidden email] |
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What is the passband of the filtering engaged in the KBPF3 when
operating at 630M? The concern at this band in many locations is BCB intermod, and generally an LPF is used in the RX chain. Is it not of concern based on on-air tests, perhaps KBPF3 is on the table for an upgrade, or an outbound LPF recommended? 73 Eric NO3M (experimental 630M license: WG2XJM) On 02/13/2015 01:27 PM, Wayne Burdick wrote: > > Q: What is the K3's 100-490 kHz receive sensitivity? What signals would I find in this range? > > A: With preamp OFF, we measured about -125 dBm at 475 kHz and -90 dBm at 250 kHz. We have not measured MDS below 250 kHz, but the receiver will gradually become less sensitive as you go lower in frequency due to band-pass filter rolloff (in the KBPF3, which is required for operation below 160 meters). These tests were made with the signal routed through the RX ANT IN or XVTR IN jacks on the KXV3 option module. The preamp is not effective in this range and must be turned off. A sub receiver (KRX3) fitted with a KBPF3 should have similar performance, whether the signal is obtained from the main path (KXV3) or from the sub's AUX RF input. > > ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by wayne burdick
On Fri,2/13/2015 10:27 AM, Wayne Burdick wrote:
> The limiting factor would then be how clean everyone else's signals are. And in the real world, this is the limiting factor. In my real world, it's an IC7600 with a legal limit amp ten miles away. > Your own transmit signal will be cleaner when using the KSYN3A, though the K3 already has one of the cleanest transmitters available, Yes. While I've seen statements (I hate the word "claim" in this kind of sentence, since it implies that the person making the statement is a liar) that the latest Flex series radios are as clean or cleaner, I've not seen ARRL measurements to confirm that. I suspect that part of that is work in the ARRL Lab with new test equipment capable of testing radios with improved dynamic range on TX. 73, Jim 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 Message delivered to [hidden email] |
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In reply to this post by wayne burdick
Wayne, >> A: With preamp OFF, we measured about -125 dBm at 475 kHz and -90 >> dBm at 250 kHz. We have not measured MDS below 250 kHz, but the >> receiver will gradually become less sensitive as you go lower in >> frequency due to band-pass filter rolloff (in the KBPF3, which is >> required for operation below 160 meters). Would it make sense to update the KBPF3 to replace (or convert) the 0.5 - 2 MHz BPF to a 2 MHz LPF? Perhaps by removing L1/L2, changing L4/L5 to 2.0 uH, removing C6 and connecting a new inductor (~10 uH) between pins 2/7 of K2? 73, ... Joe, W4TV On 2015-02-13 1:27 PM, Wayne Burdick wrote: > In response to a gazillion questions: > > * * * > > Q: What is involved in upgrading from the KSYN3 to the KSYN3A? > > A: The KSYN3A plugs into the same connectors as the KSYN3s for the main and sub synthesizers. There are minor differences in cable routing that are covered in the accompanying installation instructions. No user calibration is required for the KSYN3A, simplifying the installation process. Version 5.10 or later K3 firmware is required (presently available on our web site as a beta release). > > > Q: Will the new synthesizer module be included in future orders of the KRX3 sub receiver? > > A: Yes. But we also have limited quantities of the original synthesizer boards for those with existing K3s who wish to add a KRX3 but not upgrade the synth. Questions on specific orders should go to [hidden email]. > > > Q: What is the approximate 2-kHz dynamic range (IMDDR3) of the K3 when using the new synthesizer? > > A: Our tests show in excess of 105 dB with the narrowest filters, though there are many factors, and this should be considered approximate. (A very robust test setup is required to make these measurements.) A third party has obtained similar results, but they have not published them yet. When they do, we will update this FAQ. > > > Q: How much lower is the KSYN3A's phase noise than that of the original KSYN3? How does this affect signals? > > A: At an offset of 2 kHz, the KSYN3A's phase noise is typically 15 to 20 dB lower on a given band. Generally speaking, this means a smaller increase in the noise floor in receive mode in the presence of very strong close-in signals. The limiting factor would then be how clean everyone else's signals are. Your own transmit signal will be cleaner when using the KSYN3A, though the K3 already has one of the cleanest transmitters available, accounting for its popularity with DXpeditions and multi-transmitter contest stations. > > > Q: What is the K3's 100-490 kHz receive sensitivity? What signals would I find in this range? > > A: With preamp OFF, we measured about -125 dBm at 475 kHz and -90 dBm at 250 kHz. We have not measured MDS below 250 kHz, but the receiver will gradually become less sensitive as you go lower in frequency due to band-pass filter rolloff (in the KBPF3, which is required for operation below 160 meters). These tests were made with the signal routed through the RX ANT IN or XVTR IN jacks on the KXV3 option module. The preamp is not effective in this range and must be turned off. A sub receiver (KRX3) fitted with a KBPF3 should have similar performance, whether the signal is obtained from the main path (KXV3) or from the sub's AUX RF input. > > As for signals: there's the 600-meter band (more on that below), a large number of commercial CW beacons (for example, see www.dxinfocentre.com/ndb.htm), and other interesting phenomena. We've just begun to explore it ourselves! > > > Q: Will I notice any change in performance if I upgrade to the KSYN3A? > > A: First there's the obvious -- the ability to tune the VFOs much lower in frequency. If you're a high-speed CW operator, you should be able to hear an improvement in CW element timing at high code speeds, as well as somewhat faster receive recovery. The dynamic range of the K3 was already excellent, and its phase noise very low, so you might notice the additional improvement in these parameters only in very difficult signal conditions. > > > Q: How does the new synth affect CW operation? > > A: The KSYN3A switches faster than the KSYN3, which allows us to more precisely control CW timing. This means less "jitter" (timing variation) at high CW speeds. Many CW operators who had been using "QRQ" mode (CONFIG:CW QRQ=ON) for CW in the 35-60 WPM range will now be able to use normal CW mode (CW QRQ=OFF), meaning they no longer give up RIT and SPLIT when using fast CW. Receive recover times also improve. Note that we recently introduced a variation on CW break-in signal processing called "NEW QSK" (selected by tapping '3' in the CW WGHT menu entry). This eliminates audio T/R artifacts heard with the original algorithm ("OLD QSK"), at the expense of some slowing of receive recovery (by purging the DSP's "pipeline"). Installing a KSYN3A speeds up receive recovery for both the OLD and NEW QSK settings. > > > Q: What is required to use the 600-meter band? > > A: This band is available in some countries, often on an experimental basis. Specific restrictions may apply. A K3 fitted with a KSYN3A, as well as a KXV3 and KBPF3, can receive signals on this band, and can put out about 1 milliwatt of transmit power. An external amplifier will be needed, connected to the XVTR OUT jack. At present we don't have information on such amplifiers. You can also get on this band using an up-conversion transverter whose output is on a low HF band (also not presently supplied by Elecraft). For a general introduction to the 600-meter band, see: > > wikipedia.org/wiki/600-meter_amateur_radio_band > > > Q: Can a transverter I.F. of "0" be defined as an alternative to setting CONFIG:KXV3 to TEST? > > A: Not at this time, though we hope to add this capability. Those who frequently alternate between TEST and NOR modes can assign the KXV3 menu entry to a programmable function switch, or write a switch macro to change this menu setting as well as set up the VFO, preamp, etc., for this band. > > ______________________________________________________________ > 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 > Message delivered to [hidden email] > 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 Message delivered to [hidden email] |
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In reply to this post by Eric NO3M
The KBPF3's lowest-frequency filter has a nominal passband of 0.5-2 MHz. The rolloff is not particularly steep, but this is the reason that the MDS at 250 kHz is -90 dBm, while it's -125 dBm at 450 kHz.
Intermod should rarely be a factor because of the K3's very robust front end. Those living practically on top of an AM broadcast station typically have been through this drill already and have notch filters. If not, we can design one for you (you get to build it, though :) Wayne N6KR On Feb 13, 2015, at 10:53 AM, Eric NO3M <[hidden email]> wrote: > What is the passband of the filtering engaged in the KBPF3 when operating at 630M? The concern at this band in many locations is BCB intermod, and generally an LPF is used in the RX chain. Is it not of concern based on on-air tests, perhaps KBPF3 is on the table for an upgrade, or an outbound LPF recommended? > > 73 Eric NO3M (experimental 630M license: WG2XJM) > > On 02/13/2015 01:27 PM, Wayne Burdick wrote: >> >> Q: What is the K3's 100-490 kHz receive sensitivity? What signals would I find in this range? >> >> A: With preamp OFF, we measured about -125 dBm at 475 kHz and -90 dBm at 250 kHz. We have not measured MDS below 250 kHz, but the receiver will gradually become less sensitive as you go lower in frequency due to band-pass filter rolloff (in the KBPF3, which is required for operation below 160 meters). These tests were made with the signal routed through the RX ANT IN or XVTR IN jacks on the KXV3 option module. The preamp is not effective in this range and must be turned off. A sub receiver (KRX3) fitted with a KBPF3 should have similar performance, whether the signal is obtained from the main path (KXV3) or from the sub's AUX RF input. >> >> > > ______________________________________________________________ > 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 > Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by wayne burdick
Good idea. One of our engineers will be assigned to this when he comes up for air.
Wayne N6KR On Feb 13, 2015, at 10:58 AM, "[hidden email] [Elecraft_K3]" <[hidden email]> wrote: > Wayne, > > While we have your attention...do you have updated schematics for the K3, including this new board? The K3 schematics on the website are dated June 2010. > > Mike N2MS > ----- Original Message ----- > From: Wayne Burdick [hidden email] [Elecraft_K3] <[hidden email]> > To: Elecraft Reflector <[hidden email]> > Cc: [hidden email] <[hidden email]> > Sent: Fri, 13 Feb 2015 18:27:01 -0000 (UTC) > Subject: [Elecraft_K3] KSYN3A FAQ > > In response to a gazillion questions: > > <snip> > > * > __._,_.___ > Posted by: [hidden email] > Reply via web post • Reply to sender • Reply to group • Start a New Topic • Messages in this topic (2) > VISIT YOUR GROUP > • New Members 11 > > • Privacy • Unsubscribe • Terms of Use > . > > > __,_._,___ ______________________________________________________________ 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 Message delivered to [hidden email] |
Re: [Elecraft_K3] Re: KSYN3A FAQ
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In reply to this post by Joe Subich, W4TV-4
On Feb 13, 2015, at 11:58 AM, "'Joe Subich, W4TV' [hidden email] [Elecraft_K3]" <[hidden email]> wrote: > > Wayne, > > >> A: With preamp OFF, we measured about -125 dBm at 475 kHz and -90 > >> dBm at 250 kHz. We have not measured MDS below 250 kHz, but the > >> receiver will gradually become less sensitive as you go lower in > >> frequency due to band-pass filter rolloff (in the KBPF3, which is > >> required for operation below 160 meters). > > Would it make sense to update the KBPF3 to replace (or convert) the > 0.5 - 2 MHz BPF to a 2 MHz LPF? Perhaps by removing L1/L2, changing > L4/L5 to 2.0 uH, removing C6 and connecting a new inductor (~10 uH) > between pins 2/7 of K2? This is certainly not necessary for use of the 600-meter band, or even for listening to beacons in the 300-kHz range, which I've been doing lately. If you were really determined to improve MDS below 250 kHz, you could do this. I would start thinking about the lower-frequency limitations of the PIN diodes with large signals. 73, Wayne N6KR ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by Jim Brown-10
On 2015-02-13 2:37 PM, Jim Brown wrote: > And in the real world, this is the limiting factor. In my real > world, it's an IC7600 with a legal limit amp ten miles away. Consider yourself lucky. In my real world, it's an IC-746 and legal limit amp 0.65 miles away! > Yes. While I've seen statements (I hate the word "claim" in this kind > of sentence, since it implies that the person making the statement is > a liar) that the latest Flex series radios are as clean or cleaner, > I've not seen ARRL measurements to confirm that. No, but one can infer that from the Receiver data published by Sherwood on the Flex 6700 (receive LO Noise = 145 dBc/Hz). Given the design of those "radios" the phase noise is generally clock jitter and would be reciprocal in transmit. 73, ... Joe, W4TV ______________________________________________________________ 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 Message delivered to [hidden email] |
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Another interesting issue regarding the Flex 6xxx series (and radios with a similar direct-digital-sampling RF architecture) is that "A/D Limit" descriptor in the blocking dynamic range column in Sherwood's chart. An ADC limit is a hard one; it does not gracefully soft-limit in the presence of strong signals, like an amplifier stage. Multiple signals in the passband can cause additive peaks that hit this ADC limit sooner, causing ghost signals (IMD) to appear. 3-tone (or higher) testing may be needed to quantify the effect of the ADC limit in DDC receivers. Perhaps "A/D Limit" can then be converted into a useful number.
Wayne N6KR On Feb 13, 2015, at 12:07 PM, "Joe Subich, W4TV" <[hidden email]> wrote: > > On 2015-02-13 2:37 PM, Jim Brown wrote: >> And in the real world, this is the limiting factor. In my real >> world, it's an IC7600 with a legal limit amp ten miles away. > > Consider yourself lucky. In my real world, it's an IC-746 and legal > limit amp 0.65 miles away! > >> Yes. While I've seen statements (I hate the word "claim" in this kind >> of sentence, since it implies that the person making the statement is >> a liar) that the latest Flex series radios are as clean or cleaner, >> I've not seen ARRL measurements to confirm that. > > No, but one can infer that from the Receiver data published by Sherwood > on the Flex 6700 (receive LO Noise = 145 dBc/Hz). Given the design of > those "radios" the phase noise is generally clock jitter and would be > reciprocal in transmit. > > 73, > > ... Joe, W4TV > > ______________________________________________________________ > 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 > Message delivered to [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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On 2015-02-13 3:15 PM, Wayne Burdick wrote: > Another interesting issue regarding the Flex 6xxx series (and radios > with a similar direct-digital-sampling RF architecture) is that "A/D > Limit" descriptor in the blocking dynamic range column in Sherwood's > chart. An ADC limit is a hard one; it does not gracefully soft-limit > in the presence of strong signals, like an amplifier stage. Multiple > signals in the passband can cause additive peaks that hit this ADC > limit sooner, causing ghost signals (IMD) to appear. 3-tone (or > higher) testing may be needed to quantify the effect of the ADC limit > in DDC receivers. Perhaps "A/D Limit" can then be converted into a > useful number. In an e-mail exchange with Chen, W7AY some months ago he indicated the "number of tones" seems to be somewhere around 10. However, I'm sure that is fuzzy and depends a lot on the frequency relationship and if they are all of similar strength or there is a wide dynamic range. Perhaps the best way to test dynamic range in direct digital sampling receivers is noise power testing. Run a "notched noise signal" of a known level into the DDS receiver and increase the noise power until the noise floor in the notch increases 1 dB. 73, ... Joe, W4TV > > Wayne > N6KR > > ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by wayne burdick
A couple comments to add to Wayne's:
1. How many of you have measured the noise floor below 500-KHz? I have used my K3/10 and a SDR-IQ for receiving the 600m band for three years. The SDR-IQ display is in dBm and very accurate. The receiver MDS is -130 to -132 dBm at 500-KHz. The lowest noise floor I see with my inverted-L antenna is -115 dBm. Often it is -100 or even -90 dBm. So reality is that sky noise and local noise environment will be your receiving limit vs the MDS of the K3. Those of you who operate on 160m will recognize what I am saying. I have not gone below 300-KHz so do not know what the noise looks like down there. There is a RGPS beacon 3-miles from my house that comes in at -30dBm on 310-KHz. It would be a good propagation beacon for anyone that wants to work me on 600m (currently my antenna is down). Now if you own acreage to put up a Beverage antenna then you may get noise low enough to utilize the MDS. Then there is always adding a low noise preamp to improve MDS. 2. Many of us in the ARRL Experimental Group or with experimental licenses for operating on 600m utilize bandpass filters to reduce BC interference. I have a Clifton Labs Z10020 Rejection Filter (540-1700 KHz) which is limited to 100mw if you plan to transmit thru it. I use it only for receiving. An Anchorage station (65mi NE) on 550-KHz normally is seen at -50 dBm, drops into the noise with the filter and the broad noise sidebands disappear. http://www.cliftonlaboratories.com 73, Ed - KL7UW, WD2XSH/45 From: Wayne Burdick <[hidden email]> To: Eric NO3M <[hidden email]> Cc: [hidden email] Subject: Re: [Elecraft] KSYN3A FAQ Message-ID: <[hidden email]> Content-Type: text/plain; charset=us-ascii The KBPF3's lowest-frequency filter has a nominal passband of 0.5-2 MHz. The rolloff is not particularly steep, but this is the reason that the MDS at 250 kHz is -90 dBm, while it's -125 dBm at 450 kHz. Intermod should rarely be a factor because of the K3's very robust front end. Those living practically on top of an AM broadcast station typically have been through this drill already and have notch filters. If not, we can design one for you (you get to build it, though :) Wayne N6KR 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: [hidden email] ______________________________________________________________ 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 Message delivered to [hidden email] |
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In reply to this post by wayne burdick
Will Elecraft be offering a trade in program for the old Synth
boards? :) -- Thanks and 73's, For equipment, and software setups and reviews see: www.nk7z.net for MixW support see; http://groups.yahoo.com/neo/groups/mixw/info for Dopplergram information see: http://groups.yahoo.com/neo/groups/dopplergram/info for MM-SSTV see: http://groups.yahoo.com/neo/groups/MM-SSTV/info ______________________________________________________________ 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 Message delivered to [hidden email] |
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