++++++++++++++++++++ See also K2 Fuzzy Audio ++++++++++++++++++++ From: "Steve & Anne Ray" To: "Elecraft" Date: Wed, 23 Oct 2002 21:19:36 -0400 Subject: [Elecraft] Raspy Receive Audio and Transformers Just a note, as I had followed the Elecraft advice and kept my power supply (Astron 10A) more then 18 inches from the K2 to avoid the magnetic field affecting the K2. Well, last night I was on and the received audio was crackling and raspy, all the CW signals sounded like they were about RST 573. Needless to say the horrible thought went through my mind on what had gone wrong with the audio. Found out the problem relatively quickly, I had moved my old Heath Digital Clock to within 5 inches of the K2. I did not think that this would be a problem as the power supply for the clock only draws 600 mA. Moving the clock back to its regular position about a foot away cured the problem. Just hope this helps someone else. 73, Steve Ray K4JPN ex K1VKW EM82ep Warner Robins GA Elecraft K2 1422 Heath Fan HW-101, HW-8 ++++++++++++++++++++++ Date: Tue, 14 Jan 2003 00:51:28 -0500 From: WA9GQT at aol.com To: elecraft at mailman.qth.net Subject: [Elecraft] FYI-Raspy Audio on 160 & 80 Only Hi all! I just solved a problem of raspy audio reports that I had been working on for weeks. I have been using my K2 #1900 since Mar 2001 with great audio reports on 20, 17, & 12 meter SSB. I had done R14 mod increasing it to 10K. I used both RS & MH2 mic's with great reports! Since operating on 160m lately, I have had reports of raspy or RF getting into my audio. I tried different antennas, & extra grounding but still bad reports! Even got a bad report on 80m SSB. Thanks to a ham about 4 mi from me, I finally solved this problem. Since he could hear my signal loud enough, he could detect very low levels of this sound. Once I decreased my mic gain SSBA from 2 down to 1, the raspy noise disappered completely. I can still run compression SSBC. 3:1 and still get great reports, even with the KPA100. I never thought that the mic gain would be so frequency sensitive! Thought the list would benefit from this one! 73, Rod WA9GQT K2 #1900 Rev B with KPA100 +++++++++++++++++++ From: "f9oj" To: "David Walker" , Subject: Re: [Elecraft] Fuzzy Audio Date: Thu, 17 Apr 2003 10:57:03 +0200 Hi David Try to keep your compression as low as possible .Got the same problems as you, so I cured by : 1 /ajusting carefully the filter according to the number on the Xltl bag 2 / keeping compression down to 1 or 2, (and don't forget high compression , on any rig, isn't a solution ! ) 73 to you and all the Elecrafters Jacques ----- Original Message ----- From: "David Walker" To: Sent: Thursday, April 17, 2003 10:06 AM Subject: [Elecraft] Fuzzy Audio I was wondering if someone could give me some advise regarding KSB2 SSB poor quality transmit. I was talking to some bloke and the transmit took flight. I noticed the power meter waver when I wasn't talking and so I turned the power off. When I turned the radio people reported I was distorted and breaking up. I turned the radio off and on again.... and no solution. So I turned the radio off for 30 min's and tried again... no joy. People couldn't make out what i was saying. So I did a reset (holding 456 while turning the rig on.) I reset my filters, PLL linearisation, and Compression to 3 and set audio to 2. People now tell me my audio is fine. So... my question is... what would have gone wrong with the rig? I know it's a big question, but if anyone has had a similar problem I'd like to hear from you. This all sounds dodgy to me. Cheers all, Dave +++++++++++++++++++ From: "Bruce D. McLaughlin" To: "'David Walker'" , Subject: RE: [Elecraft] Fuzzy Audio Date: Thu, 17 Apr 2003 18:44:54 -0400 That sounds like a classic case of RF getting into the rig. If you have a dummy load, run the rig into it and listen on another receiver (if you have one). If the audio is clean, that would confirm RFI. There are a number of cures for RFI including careful grounding, rearranging the station setup, possible use of common mode or other forms of RFI chokes on the mike and transmission cable near the rig, etc. Some forms of antenna, such as end fed wires, are particularly susceptible to causing this sort of problem. You could also have a bad coax or coax connector. You may find that the problem does not happen on certain bands but is bad on others. I believe the Elecraft site has some suggestions as does the ARRL site and, I'm sure other sources. Good luck. Bruce - W8FU ++++++++++++++++++++ Reply-To: "Steve & Anne Ray" From: "Steve & Anne Ray" To: "Elecraft" , Date: Thu, 17 Apr 2003 20:19:35 -0400 Subject: [Elecraft] Fuzzy Audio. I had a similar problem on both transmit and receive. My old Heathkit digital clock was about 2 inches from the K2. Apparently the small transformer inside it was generating a magnetic field that was affecting the PLL. I could make the problem come and go simply by moving the clock from 2 inches to 6 inches from the K2. The clock only drew about 200 mA so I can imagine a regular 3 or 4 amp power supply could really affect the K2. 72, Steve Ray K4JPN ex K1VKW EM82ep Warner Robins GA Elecraft K2 1422 & KPA-100 Heath Fan HW-101, HW-8 ++++++++++++++++++++ Date: Tue, 20 May 2003 10:51:03 -0700 From: Eric Swartz WA6HHQ - Elecraft Organization: Elecraft To: john FRANCIS Cc: Elecraft List Subject: Re: [Elecraft] Very rough Note Sounds like you have a linear supply right next to or under the K2. It will modulate the K2's PLL and BFO oscillators with the transformer's magnetic field. Move the power supply a foot or two further away and your problems should subside. 73, Eric WA6HHQ ----- john FRANCIS wrote: > Help before my family have me taken away. Completed my K2 #3111 This afternoon. Rx appears to work OK. On transmit monitoring on my main RX mI am putting out a very rough note sounds like 594 or even worst just like the old ruski transmiiters. > > Appreciate any suggestions. Don't know if anyone else on the net has had similar problem. Thanks in anticipation > > 73's John G3LWI ++++++++++++++++++