Re: [Elecraft] Headphone output levels on the K2?
Steve Kallal wrote: I have a requirement that my rigs have relatively high audio output wo/ distortion from the headphone jack. I have a moderate hearing loss, about 45 db down especially in the speech region. The audiologists calls that I've had that sort of loss in one ear since childhood and some in the other, and I did get prescribed an aid as a child, although I haven't been very good at using it. I think the best thing about a kit like the K2 is that adding a small audio stage internally before the headphone jack doesn't ruin the rig. But I would hope that won't be necessary. As others have said, you could also reduce the series resistors on the headphone output, although you might need to modify the shunt capacitors as well; I'm not sure of the function of these (could be audio low pass, or could be RF pickup blocking). You won't get 45dB of gain without transformer coupling, as I don't think there is enough power supply voltage for that. Also, noise cancelling headphones normally have an amplifier, so, in cancelling mode, increase the wanted as well as suppressing unwanted sound. Mine are vulnerable to GSM mobile phone signals, so might have RF pickup problems. (My interest in Elecraft is to try getting back into amateur radio, so I haven't used them near amateur transmissions, yet.) Also I don't wear my hearing aids with headphones because of feeback. I went with behind the ear hearing aids. Maybe a heaphones with larger deeper cups would help. Most hearing aids, including state supplied ones, in the UK, have a T setting, which uses an induction loop pickup, rather than a microphone. You can use this with headphones with reasonable field leakage, or special, silent, ones. I don't know how sensitive they are to RF pickup. For some, you can get shoes that allow them to be connected to normal domestic audio equipment. I'm not sure if these couple acoustically, or whether they match a connector on the aid. Theoretically, you could also get headphones with hearing aid type ear moulds. In the past, when hearing aids had output transducers that clipped directly onto the earmould, the clip was the same as used in professional head sets. Nowadays, they couple acoustically, with a plastic tube, so there might not be direct compatibility. I welcome comments from those who are familiar with the headphone output Unfortunately, I've not built it far enough to hear more than sidetone yet. -- David Woolley Emails are not formal business letters, whatever businesses may want. RFC1855 says there should be an address here, but, in a world of spam, that is no longer good advice, as archive address hiding may not work. ___ 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] Headphone output levels on the K2?
I have an old set of full size sony headphones that give way more than enough audio output for my moderate hearing loss. Most headphones are rated for the level of audio out for power in, and the ones that cover the ears seem to be more comfortable for me and reduce any outside noise. How you set up the agc effects the audio output level of the k2, and there are resistors that can be changed or eliminated in the headphone circuit, or you could plug the headphones in the ext speaker output. You can also change the tone of the CW to get in a range that you might hear better, I seem to like a much higher CW note than many operators as I am up against the BFO range limit on my K2. Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Steve Kallal Sent: Monday, June 11, 2007 11:16 AM To: elecraft@mailman.qth.net Subject: [Elecraft] Headphone output levels on the K2? Hello again! I have a requirement that my rigs have relatively high audio output wo/ distortion from the headphone jack. I have a moderate hearing loss, about 45 db down especially in the speech region. The audiologists calls that MODERATE. 60 db down is considered more serious. Wow! Even the FCC wants tx spurs down 40 db or so. I have been using a FlexRadio SDR-1000 rig mostly because of the great DSP. One of the advantages is the external Firewire sound card which is able to boost audio into the headphones. I even found a cheap set of KOSS UR29 headphones have more output than my Heil's. The headphone output on the PRO II causes the headphone audio to distort before its loud enough for me. But the simplicity of CW seems wasted on a lot of hardware hanging off a PC. I am a new CW op. Started last fall getting my code speed up after 31 years as a ham and 29 years on HF. Do about 15 wpm on a good day. A friend of mine thinks the K2 is a good rig for copying weak CW popping through the QRN. The SDR is the best I've found so far. It certainly puts my PRO II to shame on rx. I think the best thing about a kit like the K2 is that adding a small audio stage internally before the headphone jack doesn't ruin the rig. But I would hope that won't be necessary. Also I don't wear my hearing aids with headphones because of feeback. I went with behind the ear hearing aids. Maybe a heaphones with larger deeper cups would help. I welcome comments from those who are familiar with the headphone output level on the K2. I don't want to drag around some external mixer to listen to CW, hi hi. 73, Steve N6VL FISTS #12707 SKCC #2383 [EMAIL PROTECTED] ___ 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
[Elecraft] Headphone output levels on the K2?
Some headfones have MUCH more gain with the K2 than others. the Kenwood HS-5 is a low impedance phone. I put it on the speaker jack. with that, I have to turn the AF gain down to almost 8 o'clock and the RF gain down to about 10 o'clock to keep from blowing my head off with volume. the HS-5 is monoaural as it comes form the manufacturer. it came with a 1/4 inch jack. Change it to an 1/8 inch monoaural, and it will plug right in to the speaker jack on the back of the K2. I reqired mine to stereo which can easily be done by popping the back off the the headfones. The cable is already three wire, and simply requires moving one lead in the can to make it stereo. If used with just a K2, however, this modification is not necessary. 72, Fred - kt5x ___ 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] Headphone output levels on the K2?
Hello again! I have a requirement that my rigs have relatively high audio output wo/ distortion from the headphone jack. I have a moderate hearing loss, about 45 db down especially in the speech region. The audiologists calls that MODERATE. 60 db down is considered more serious. Wow! Even the FCC wants tx spurs down 40 db or so. I have been using a FlexRadio SDR-1000 rig mostly because of the great DSP. One of the advantages is the external Firewire sound card which is able to boost audio into the headphones. I even found a cheap set of KOSS UR29 headphones have more output than my Heil's. The headphone output on the PRO II causes the headphone audio to distort before its loud enough for me. But the simplicity of CW seems wasted on a lot of hardware hanging off a PC. I am a new CW op. Started last fall getting my code speed up after 31 years as a ham and 29 years on HF. Do about 15 wpm on a good day. A friend of mine thinks the K2 is a good rig for copying weak CW popping through the QRN. The SDR is the best I've found so far. It certainly puts my PRO II to shame on rx. I think the best thing about a kit like the K2 is that adding a small audio stage internally before the headphone jack doesn't ruin the rig. But I would hope that won't be necessary. Also I don't wear my hearing aids with headphones because of feeback. I went with behind the ear hearing aids. Maybe a heaphones with larger deeper cups would help. I welcome comments from those who are familiar with the headphone output level on the K2. I don't want to drag around some external mixer to listen to CW, hi hi. 73, Steve N6VL FISTS #12707 SKCC #2383 [EMAIL PROTECTED] ___ 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
