Tunable carrier (birdie) 20445khz
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While looking for a source of some steady carrier interference on the 20M and 15M bands, I noticed that one of them at 21.017.9 Khz moved (on the P3 screen) in proportion to the tuning of the K3. Obviously a birdie as I checked with no antenna. The birdie had side lobes - i.e. there were weak carriers either side at 12Khz offsets. Tuning around, I found what appears to be the fundamental at 20445.11 kHz. The freq's are with rig on CW normal - the freq's listed change with mode. Turning P3 off makes no difference.
I would like to get rid of these or minimize the levels - any ideas? Gill W4RYW |
Re: Tunable carrier (birdie) 20445khz
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Gill,
May I suggest you open the top of the K3 and give each one of the TMP cables a slight turn in their sockets while applying a bit of pressure toward the socket. Grasp the "ears" on the TMP connector, do not try to twist it holding only the cable. Look in the assembly manual and make certain the TMP cables are positioned as shown in the photos. No guarantee it will fix this spur, but it is a good starting point. The Birdie Removal Tool can be used if that does not correct it for you. 73, Don W3FPR On 8/20/2011 1:06 PM, Gill W4RYW wrote: > While looking for a source of some steady carrier interference on the 20M and > 15M bands, I noticed that one of them at 21.017.9 Khz moved (on the P3 > screen) in proportion to the tuning of the K3. Obviously a birdie as I > checked with no antenna. The birdie had side lobes - i.e. there were weak > carriers either side at 12Khz offsets. Tuning around, I found what appears > to be the fundamental at 20445.11 kHz. The freq's are with rig on CW normal > - the freq's listed change with mode. Turning P3 off makes no difference. > > I would like to get rid of these or minimize the levels - any ideas? > 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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So...what is the best way to check for birdies...no antenna, dummy load,
shorted coax plug? And i assume you want the bandwidth wide and probably in CW mode?? On 8/20/2011 1:22 PM, Don Wilhelm wrote: > Gill, > > May I suggest you open the top of the K3 and give each one of the TMP > cables a slight turn in their sockets while applying a bit of pressure > toward the socket. Grasp the "ears" on the TMP connector, do not try to > twist it holding only the cable. > > Look in the assembly manual and make certain the TMP cables are > positioned as shown in the photos. > > No guarantee it will fix this spur, but it is a good starting point. > > The Birdie Removal Tool can be used if that does not correct it for you. > > 73, > Don W3FPR > > On 8/20/2011 1:06 PM, Gill W4RYW wrote: >> While looking for a source of some steady carrier interference on the 20M and >> 15M bands, I noticed that one of them at 21.017.9 Khz moved (on the P3 >> screen) in proportion to the tuning of the K3. Obviously a birdie as I >> checked with no antenna. The birdie had side lobes - i.e. there were weak >> carriers either side at 12Khz offsets. Tuning around, I found what appears >> to be the fundamental at 20445.11 kHz. The freq's are with rig on CW normal >> - the freq's listed change with mode. Turning P3 off makes no difference. >> >> I would like to get rid of these or minimize the levels - any ideas? >> > ______________________________________________________________ > 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 > -- 73, Gary K9GS Check out K9NS on the web: http://www.k9ns.com Greater Milwaukee DX Association: http://www.gmdxa.org Society of Midwest Contesters: http://www.w9smc.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: Tunable carrier (birdie) 20445khz
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Gary,
I would suggest a well shielded dummy load connected with a very short piece of coax. Second best would be the shorted coax plug. Yes, CW mode. Make certain what you are listening to tunes faster than a normal signal - if it tunes at the normal rate, it is not a birdie, but a real signal close to your receiver, and there is nothing you can do in the K3 to eliminate it - short of putting the K3 in an entirely sealed shielding box. With no antenna connected, even the short wires inside the K3 or just the open connector center conductor can pick up a response from a local signal. 73, Don W3FPR On 8/20/2011 2:30 PM, Gary K9GS wrote: > So...what is the best way to check for birdies...no antenna, dummy load, > shorted coax plug? > > And i assume you want the bandwidth wide and probably in CW mode?? > > On 8/20/2011 1:22 PM, Don Wilhelm wrote: >> Gill, >> >> May I suggest you open the top of the K3 and give each one of the TMP >> cables a slight turn in their sockets while applying a bit of pressure >> toward the socket. Grasp the "ears" on the TMP connector, do not try to >> twist it holding only the cable. >> >> Look in the assembly manual and make certain the TMP cables are >> positioned as shown in the photos. >> >> No guarantee it will fix this spur, but it is a good starting point. >> >> The Birdie Removal Tool can be used if that does not correct it for you. >> >> 73, >> Don W3FPR >> >> On 8/20/2011 1:06 PM, Gill W4RYW wrote: >>> While looking for a source of some steady carrier interference on the 20M and >>> 15M bands, I noticed that one of them at 21.017.9 Khz moved (on the P3 >>> screen) in proportion to the tuning of the K3. Obviously a birdie as I >>> checked with no antenna. The birdie had side lobes - i.e. there were weak >>> carriers either side at 12Khz offsets. Tuning around, I found what appears >>> to be the fundamental at 20445.11 kHz. The freq's are with rig on CW normal >>> - the freq's listed change with mode. Turning P3 off makes no difference. >>> >>> I would like to get rid of these or minimize the levels - any ideas? >>> >> ______________________________________________________________ >> 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: Tunable carrier (birdie) 20445khz
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In reply to this post by Gill W4RYW
Weaker birdies can be drowned out by band noise. If you want to find these
weaker birdies, disconnect the antenna. As for bandwidth and mode, you should use the mode(s) and bandwidth(s) you are most likely to use at that frequency - the birdies change frequency when you change modes and/or when you change between roofing filters with different offsets. 73, Rich VE3KI K9GS wrote: > So...what is the best way to check for birdies...no antenna, dummy load, > shorted coax plug? > > And i assume you want the bandwidth wide and probably in CW mode?? ______________________________________________________________ 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: Tunable carrier (birdie) 20445khz
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In reply to this post by Gary K9GS
Thanks for the suggestions guys - for those of you with P3's - tune to 20445.11 on CW nor mode and take a look with the span on the P3 set at 200khz. A regular picket fence of birdies! (at least on my K3)
73 Gill |
Re: Tunable carrier (birdie) 20445khz
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Not seen here.
73, Bill K9YEQ -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Gill W4RYW Sent: Saturday, August 20, 2011 4:10 PM To: [hidden email] Subject: Re: [Elecraft] Tunable carrier (birdie) 20445khz Thanks for the suggestions guys - for those of you with P3's - tune to 20445.11 on CW nor mode and take a look with the span on the P3 set at 200khz. A regular picket fence of birdies! (at least on my K3) 73 Gill ______________________________________________________________ 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 Gill W4RYW
one spike zero beat on the peak on the P3 @ 20.444939
tone sounds like about 580hz only seen on CW-N GB & 73 K5OAI Sam Morgan On 8/20/2011 4:10 PM, Gill W4RYW wrote: > Thanks for the suggestions guys - for those of you with P3's - tune to > 20445.11 on CW nor mode and take a look with the span on the P3 set at > 200khz. A regular picket fence of birdies! (at least on my K3) > > 73 Gill ______________________________________________________________ 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 Gill W4RYW
Hi Gill,
If you do a search in the achrive of this reflector, you will find a number of ways to eliminate or reduce the birdies. Here are some examples: 1. re-sit the TMP connectors around the KSY3 and RF area; 2. slightly alter the position of the TMP cables TNX & 73, Johnny VR2XMC 從︰ Gill W4RYW <[hidden email]> 收件人︰ [hidden email] 傳送日期︰ 2011年08月21日 (週日) 5:10 AM 主題︰ Re: [Elecraft] Tunable carrier (birdie) 20445khz Thanks for the suggestions guys - for those of you with P3's - tune to 20445.11 on CW nor mode and take a look with the span on the P3 set at 200khz. A regular picket fence of birdies! (at least on my K3) 73 Gill -- View this message in context: http://elecraft.365791.n2.nabble.com/Tunable-carrier-birdie-20445khz-tp6706620p6707083.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 |
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In reply to this post by Gill W4RYW
The Birdie near 21.017 is a fast tuning birdie. You can remove it by following the instructions for SIG RMV [T] on page 59 of the Owner's Manual Revision D9, Dec. 7, 2010. As for the one near 20.445, that frequency is not within any amateur radio allocation I am aware of. What's all the hullabaloo about? 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member On Sat, 20 Aug 2011 10:06:43 -0700 (PDT), Gill W4RYW <[hidden email]> wrote: >While looking for a source of some steady carrier interference on the 20M and >15M bands, I noticed that one of them at 21.017.9 Khz moved (on the P3 >screen) in proportion to the tuning of the K3. Obviously a birdie as I >checked with no antenna. The birdie had side lobes - i.e. there were weak >carriers either side at 12Khz offsets. Tuning around, I found what appears >to be the fundamental at 20445.11 kHz. The freq's are with rig on CW normal >- the freq's listed change with mode. Turning P3 off makes no difference. > >I would like to get rid of these or minimize the levels - any ideas? > >Gill W4RYW ______________________________________________________________ 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
Amateur Radio Operator N5GE
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N5GE said what I had been thinking. Let me put it another way: all receivers
have birdies, but as long as the majority of them fall outside the amateur bands we should be happy about that. That shows good skill and judgement on the part of the receiver designer. Spend your energy removing in-band birdies, but only if they bother you. Regards, Al W6LX ______________________________________________________________ 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: Tunable carrier (birdie) 20445khz
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In reply to this post by AC7AC
Ron and I will have to just disagree with the definition of a "birdie" -
and it is only a matter of definition. My definition is the result of multiples of the various signals and oscillator frequencies present in the receiver, and since they are always multiples greater than 1 of any signal (or oscillator), will always result in a fast tuning response. OTOH, there are unavoidable mixing products in any down-conversion receiver that will tune as a normal signal. The goal of the designer is to choose the IF frequencies to keep those spurious responses out of the bands of interest to the target users - in this case, the ham bands. So, if your definition of "birdies" agrees with Ron's, so be it - I will continue to refer to extraneous direct mixing products (those responses that do not produce fast tuning signals) as spurious responses. It is just a matter of definition. BTW, this is one of the advantages of up-conversion - those direct responses are so far away from the desired signal that they do not become troublesome, but up-conversion designs have their own share of troublesome problems. 73, Don W3FPR On 8/20/2011 8:06 PM, Ron D'Eau Claire wrote: > I show one birdie here. It's a "normal tuning" (not double rate) birdie which, with great respect for Don, I will disagree with him and say that not all birdies tune at accelerated rates if one defines a birdie as an internally-generated unwanted signal. That birdie is at about -100 dBm. > > If I turn on the preamp and connect a dummy load, a row of lower level birdies does appear, but they are completely buried in normal band noise (here at -140 dBm) with an antenna connected. > > As others pointed out, you can try moving TMP cables or, more simply, applying the "birdie removal" software. The latter does not cause a hole at that frequency. It just moves the oscillator frequencies around as you tune to that frequency so that when you are tuned there the birdie is somewhere else. > > Ron AC7AC > > -----Original Message----- > > Thanks for the suggestions guys - for those of you with P3's - tune to > 20445.11 on CW nor mode and take a look with the span on the P3 set at > 200khz. A regular picket fence of birdies! (at least on my K3) > > 73 Gill > > > -- > > ______________________________________________________________ > 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 alorona
On 8/20/2011 7:30 PM, Al Lorona wrote:
> N5GE said what I had been thinking. Let me put it another way: all receivers > have birdies, but as long as the majority of them fall outside the amateur bands > we should be happy about that. That shows good skill and judgement on the part > of the receiver designer. Rx birdies are not the problem here, Ethernet hash and local oscillator harmonics from all the wi-fi stuff *is*. If I could get rid of that, I might actually hear a birdie generated in the rx. Fred K6DGW Auburn CA ______________________________________________________________ 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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