Setting K2 AGC
Locked
 
|
Rich and the group,
In reading the some of last week's posts about using Spectrogram to adjust L34 of the K2 for best s/n ratio, I thought it certainly couldn't hurt to give it a shot. The posts also said that the AGC threshold should be re-adjusted once this is done. In looking over the K2 manual (I have Ver. C of the manual - K2 s/n 1103), I didn't see any reference to setting the K2 threshold. Could someone please point me in the right direction as for as setting the AGC. Thanks for your usual help Tom, WB2QDG k2 1103 -----Original Message----- From: Rich Lentz <[hidden email]> To: [hidden email] <[hidden email]>; 'john' <[hidden email]> Date: Sunday, October 10, 2004 4:17 PM Subject: RE: [Elecraft] Audio levels in K2 Make sure that L34 is set properly before you set the AGC. There could be a lot of unwanted (unreceived) noise masking a proper AGC setting difficult or incorrect. I accidentally discovered the following technique while playing with Spectrogram. It is easy and it made a big difference in receive signal and MDS. I had meant to put this hint on the reflector long ago and keep forgetting. -------- How to best adjust L34 - "I.F. Amplifier Alignment" in the section of "Alignment and Test Part II," using Spectrogram. Follow the instructions for "I.F. Amplifier Alignment." When you get to the last step plug the PC sound card into the Speaker Jack (not Headphone as it attenuates some high frequencies). Viewing the display with either Spectrogram (or equivalent) or even DigiPan (or equivalent - Waterfall works best), you will notice some noise spread across the spectrum displayed. Make sure the XFIL is set for FL-1 OP-1. Now continue to adjust L34 for a compromise of the lowest displayed noise and the highest level of the tone. You will find a point where the noise is almost non existent. You may need to turn up the volume as you get close to a null. After making this adjustment, reset (align) the AGC. Even though I had adjusted this to what I thought was the best by "ear," after using this method and then re-adjusting the ARC threshold. I was amazed at the difference in sensitivity and audio level. I believe this is one of the problems/reasons some people complain about "low output volume." Rich, KE0X _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
|
|
Hi Tom
Like me you have a pre 3000 K2. After Serial Nr.3000 R1 56K on the control board was changed for a preset, so that the AGC level could be adjusted. so adjusting the AGC level only applies to K2's after Serial Nr. 3000 73 de Gordon G3ZFZ (K2 # 2746) [hidden email] Mail certified virus free courtesy of Norton Internet Security 2004 ----- Original Message ----- From: "Tom Mc" <[hidden email]> To: "Rich Lentz" <[hidden email]>; <[hidden email]>; "'john'" <[hidden email]> Sent: Sunday, October 17, 2004 5:16 AM Subject: [Elecraft] Setting K2 AGC > Rich and the group, > > In reading the some of last week's posts about using Spectrogram to adjust > L34 of the K2 for best s/n ratio, I thought it certainly couldn't hurt to > give it a shot. > > The posts also said that the AGC threshold should be re-adjusted once this > is done. In looking over the K2 manual (I have Ver. C of the manual - K2 > s/n 1103), I didn't see any reference to setting the K2 threshold. Could > someone please point me in the right direction as for as setting the AGC. > > Thanks for your usual help > Tom, WB2QDG > k2 1103 > > > > -----Original Message----- > From: Rich Lentz <[hidden email]> > To: [hidden email] <[hidden email]>; 'john' > <[hidden email]> > Date: Sunday, October 10, 2004 4:17 PM > Subject: RE: [Elecraft] Audio levels in K2 > > > Make sure that L34 is set properly before you set the AGC. There could be > a > lot of unwanted (unreceived) noise masking a proper AGC setting difficult > or > incorrect. I accidentally discovered the following technique while > playing > with Spectrogram. It is easy and it made a big difference in receive > signal > and MDS. I had meant to put this hint on the reflector long ago and keep > forgetting. > > > -------- > How to best adjust L34 - "I.F. Amplifier Alignment" in the section of > "Alignment and Test Part II," using Spectrogram. > > Follow the instructions for "I.F. Amplifier Alignment." When you get to > the > last step plug the PC sound card into the Speaker Jack (not Headphone as > it > attenuates some high frequencies). Viewing the display with either > Spectrogram (or equivalent) or even DigiPan (or equivalent - Waterfall > works > best), you will notice some noise spread across the spectrum displayed. > Make > sure the XFIL is set for FL-1 OP-1. Now continue to adjust L34 for a > compromise of the lowest displayed noise and the highest level of the > tone. > You will find a point where the noise is almost non existent. You may > need > to turn up the volume as you get close to a null. After making this > adjustment, reset (align) the AGC. > > Even though I had adjusted this to what I thought was the best by "ear," > after using this method and then re-adjusting the ARC threshold. I was > amazed at the difference in sensitivity and audio level. I believe this > is > one of the problems/reasons some people complain about "low output > volume." > > Rich, > KE0X > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
«
Return to Elecraft
|
1 view|%1 views
| Free forum by Nabble | Edit this page |