+++++++++++++++++++ To: elecraft at mailman.qth.net Date: Wed, 10 Apr 2002 17:36:29 -0500 From: n4so at juno.com Subject: [Elecraft] Attenuator audio "pop" in K1 I have five extra minature 10 uH RF chokes if you are interested in this easy and quick modification to the Attenuator audio pop. SASE and $1 to C. Brown, 12165 Miller Lane, Grand Bay, AL 36541. From: Wayne Burdick To: Mike Attenuator on/off audio "pop" elimination: Install miniature 10 or 15 uH RF choke between pins 3 and 8 of relay K1 on the bottom of the RF board. One part that fits between the pins is Mouser part nr. 434-21-100 Fastron Epoxy Coated chokes, 10uH, color code brown black black. The location of Relay K1 is near the middle of the board-- turn the board over on the top side to see where Relay K1 is located. The bottom cover is the only cover required to be removed. Pin 3 is the middle pin or number 3 counting from the top left, and pin 8 is the pin across. The 10 uF choke will fit across the pins with short leads. This mod will reduce or eliminate the audio "pop". Ken Brown-N4SO Mobile, AL EM50tk Elecraft K-1 4 ele. monoband yagi N4SO at juno.com ++++++++++++++++++ To: n4so at juno.com Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] Attenuator audio "pop" in K1 From: "Steve Lawrence" Date: Wed, 24 Apr 2002 10:06:49 -0400 Ken, I installed the inductor in my K1 last night -- but only after careful listening for the Attenuator "pop". Prior to making the modification, the pop was particularly evident in a pair of light-weight, hook over the ear/stick in - ear type Sony headphones, and while listening to strong signals -- just where one might turn on the Attenuator. It wasn't particularly objectionable, but there none the less. Installation of the inductor smooooothed out the pop subtly. The volume transitions from soft to loud, but I have the sense the transition is more of a curve and not a spike. I would recommend this quick and simple modification to anyone who is experiencing and would like to minimize this anomaly. Thanks for your help! 73, Steve aa8af n4so at juno.com 04/23/2002 09:27 PM To: Steve.Lawrence at ITWFEG.COM cc: Subject: Re: [Elecraft] Attenuator audio "pop" in K1 Steve, Yes, you can identify Relay K1 from the top if you have not mounted your speaker. It is almost in the middle of the PC board next to R16 and R18 and C31. Flip it over on the bottom and take out the screws holding the bottom cover. Identify Relay K1 from the bottom side. >From the top left count down to the number 3 pin. Across from 3 is 8 and the 10 uH will fit between the pins by cutting the leads short and soldering pins 3 and 8 with a small amount of solder. Check for shorts... Reattach the bottom cover and test it. Ken Brown-N4SO Mobile, AL EM50tk Elecraft K-1 4 ele. monoband yagi N4SO at juno.com ++++++++++++++++++