Elecraft

K2 RF Gain Control

Classic

List

Threaded

5 messages Options

KD0Q

K2 RF Gain Control

I have a new to me K2 SN in the 1200's that appears to have a flaky RF Gain
control. The lightest of touch on the knob triggers what I think is AGC.
The receiver goes silent for a few seconds, longer with slow AGC. Is it
the pot or is there something else I should be looking at?

If I need to replace the RF Gain pot, what other updates should I do while
I've got the panel off?

Thanks.

73, Glenn KD0Q
______________________________________________________________
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]

Don Wilhelm

Re: K2 RF Gain Control

Glenn,

It does sound like the RF Gain pot has become scratchy - replace it,
don't even bother with temporary fixes like cleaning stuff.

With that serial number, replace both the RF Gain pot and the AF Gain
pot. While you have the front panel board removed from the metalwork, I
would recommend that you do the entire Alternate AF Gain Wiring Mod. It
involves all three boards, but no parts - only trace cuts and added wire.

73,
Don W3FPR

On 8/15/2019 3:49 PM, KD0Q wrote:
> I have a new to me K2 SN in the 1200's that appears to have a flaky RF Gain
> control. The lightest of touch on the knob triggers what I think is AGC.
> The receiver goes silent for a few seconds, longer with slow AGC. Is it
> the pot or is there something else I should be looking at?
>
> If I need to replace the RF Gain pot, what other updates should I do while
> I've got the panel off?
>
______________________________________________________________
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]

Keith N6JPA

Re: K2 RF Gain Control

In reply to this post by KD0Q

The first thing you should check is dust on the control variable
resistor. Using a different variable resistor will give you a quick answer.

73, Keith

KM6WIZ

On 8/15/19 12:49 PM, KD0Q wrote:

> I have a new to me K2 SN in the 1200's that appears to have a flaky RF Gain
> control. The lightest of touch on the knob triggers what I think is AGC.
> The receiver goes silent for a few seconds, longer with slow AGC. Is it
> the pot or is there something else I should be looking at?
>
> If I need to replace the RF Gain pot, what other updates should I do while
> I've got the panel off?
>
> Thanks.
>
> 73, Glenn KD0Q
> ______________________________________________________________
> 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]

Don Wilhelm

Re: K2 RF Gain Control

All the pots in the K2 are sealed - no way for either dust or cleaning
fluids to get into the pot workings.

To substitute a different variable resistor, one would have to remove
the pot from the board - may as well just change it. Order a new one
from Elecraft.

73,
Don W3FPR

On 8/15/2019 4:26 PM, Keith wrote:
> The first thing you should check is dust on the control variable
> resistor. Using a different variable resistor will give you a quick answer.
>
> 73, Keith
>
______________________________________________________________
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]

KD0Q

Re: K2 RF Gain Control

Thanks Don & Keith

I'm going to replace both pots and do the wiring mod. Also saw in the
archives where the earphone jack can be an issue and will replace that
too.

73, Glenn KD0Q

On Thu, Aug 15, 2019 at 4:03 PM Don Wilhelm <[hidden email]> wrote:

> All the pots in the K2 are sealed - no way for either dust or cleaning
> fluids to get into the pot workings.
>
> To substitute a different variable resistor, one would have to remove
> the pot from the board - may as well just change it. Order a new one
> from Elecraft.
>
> 73,
> Don W3FPR
>
> On 8/15/2019 4:26 PM, Keith wrote:
> > The first thing you should check is dust on the control variable
> > resistor. Using a different variable resistor will give you a quick
> answer.
> >
> > 73, Keith
> >
> ______________________________________________________________
> 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]
>
>