[Elecraft] Ok, K2 progresses but now no audio.
I am testing the 40 meter receive and peaking filters at stage II testing. I got the problem with the PLL licked and everything was working as advertised. Now I cannot get any audio out of the radio. No hum, no hiss, nothing with an antenna connected. I do get side tone and spot tone, so that tells that the audio amp is working. Where should I start? Jess EACH ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
RE: [Elecraft] Ok, K2 progresses but now no audio.
Jess, Where and how you start depends on what test equipment you have available. To begin, we need to know whether the problem is in the audio stages or in the remainder of the receiver. Do you have a 'scope available? How about an audio signal generator? Do you have a computer with a sound card that can be used as an audio source? Do you have an audio amplifier available with a phono or mic input available? You can connect an audio amplifier input to the RF board J5 location (pin 2 is ground and pins 1 and 3 are the outputs from the product detector. If you can hear anything through the external audio amp with that setup, the receiver is working up through the product detector. Injecting an audio signal into RF Board J5 pin 1 or pin 3 (ground connection to pin 2 should produce an amplified audio signal in the headphones if the audio stages are working. You can use a computer sound card (line out or speaker out) as the audio source - play a CD on the computer and listen for any output from the K2 headphones (first make certain you can hear the computer audio through the normal computer speakers to verify that the setup is correct). The fact that you have sidetone only shows that the final audio amplifier IC is capable of output, the sidetone signal is injected into that IC separate from the receiver audio path. What I am really saying is that we need to know which half of the receiver is at fault here - audio stages or RF/IF, product detector stages. 73, Don W3FPR -Original Message- I am testing the 40 meter receive and peaking filters at stage II testing. I got the problem with the PLL licked and everything was working as advertised. Now I cannot get any audio out of the radio. No hum, no hiss, nothing with an antenna connected. I do get side tone and spot tone, so that tells that the audio amp is working. Where should I start? Jess EACH -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.338 / Virus Database: 267.10.10/73 - Release Date: 8/15/2005 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] Ok, K2 progresses but now no audio.
Jess, Make sure you have the jumpers installed in place of R18 R19 on the bottom of the control board. These jumpers provide the path for the output of the product detector U11 on the RF board. If no go, check the RF board jumpers W1, W6, W5, W2 and W3 to make sure the RF is getting to the receiver preamp, mixer, the variable bandwidth crystal filter and then to the IF Amp and Product detector. From the product detector, PD1 and PD2 go through RF board J7 to P2 on the control board. On the control board, you've got Q6 and Q7 which disconnect the AF amp when transmitting. On Wed, 17 Aug 2005 19:17:32 -0600, Jess Gypin [EMAIL PROTECTED] wrote: I am testing the 40 meter receive and peaking filters at stage II testing. I got the problem with the PLL licked and everything was working as advertised. Now I cannot get any audio out of the radio. No hum, no hiss, nothing with an antenna connected. I do get side tone and spot tone, so that tells that the audio amp is working. Where should I start? Jess EACH ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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: Elecraft@mailman.qth.net 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
