Re: [drakelist] TR-7 Receiver Noise
Carel, PA0CMU [EMAIL PROTECTED] made an utterence to the drakelist gang -- Hi Dieter and group, Unfortunately, I don't remember which transistor it was. It most likely was located on the 2nd IF / Audio board. It is Q1113 a 2N3904 (the last stage before the audio IC) who caused a same kind of noise and rumble in the TR7A of PA3AJI. The replacement is a BC549, a low noise type transistor. Carel - PA0CMU. _ MSN Zoeken, voor duidelijke zoekresultaten! http://search.msn.nl -- On Behalf of Carel, PA0CMU [EMAIL PROTECTED] Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
Re: [drakelist] TR-7 Receiver Noise
Harold Polk [EMAIL PROTECTED] made an utterence to the drakelist gang -- On Dec 13, 2004, at 7:36 AM, Carel, PA0CMU wrote: Carel, PA0CMU [EMAIL PROTECTED] made an utterence to the drakelist gang -- Hi Dieter and group, Unfortunately, I don't remember which transistor it was. It most likely was located on the 2nd IF / Audio board. It is Q1113 a 2N3904 (the last stage before the audio IC) who caused a same kind of noise and rumble in the TR7A of PA3AJI. The replacement is a BC549, a low noise type transistor. I have a TR7 that tends to break into osc. in the audio area. The sound is hear on RX and is also present faintly on TX. A Drake engineer said he had never heard of it happening before and could not find it when the radio was sent to Drake for service. The sound begins after about 30 minutes of use and can be stopped by keying the mic but sometimes it will not stop at all. Anyone heard of this happening before and if you have what did you do to fix it. Serial number of radio is a little on the plus side of 4000 I don't have the extender boards so working on the radio if a bit difficult for this type of thing. Harold -- On Behalf of Harold Polk [EMAIL PROTECTED] Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
Re: [drakelist] TR-7 Receiver Noise
Dieter Horst [EMAIL PROTECTED] made an utterence to the drakelist gang -- Hi Vic and group, some years ago I replaced a 'semi-faulty' transistor in the audio chain which caused some kind of noise or rumble. Unfortunately, I don't remember which transistor it was. It most likely was located on the 2nd IF / Audio board. In general, try to find out whether your noise is caused by the audio amp or some other source. What happens if you disconnect the antenna? BTW, the hum from the switch line for the PS7 mentioned by other list members, I encountered here as well. 73, Dieter DL5RDO [EMAIL PROTECTED] made an utterence to the drakelist gang -- Greetings. I recently put a TR-7 on the air that I purchased several months ago. All is fine except that there is what I can best describe as a low frequency rumble noise that is most noticable when using headphones. It is very audible even with the RF gain set to max and the audio gain set to min. I have listed with another receiver and do not hear this noise, so I don't think I have any interference in the shack. When tuning in signals, there does not appear to be any distortion, but the background noise is very noticable. Any suggestions greatly appreciated. Vic K5TAG -- On Behalf of [EMAIL PROTECTED] Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ -- -- On Behalf of Dieter Horst [EMAIL PROTECTED] Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] TR-7 Receiver Noise
Carel, PA0CMU [EMAIL PROTECTED] made an utterence to the drakelist gang -- Hello Vic, It might be the powerline wiring from the on/off switch on the front panel to the connector on the rear panel. The 60 Hz /110V signal introduces a hum in the audio circuits. We modified the PS-7 by mounting a switch on the frontpanel and disabled the original on/off switching. Due to that, the PA fan must be replaced too. We used a cheap 12V computer fan. Now you can use your TR7 with forced cooling in the field too! 73, Carel - PA0CMU. From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Subject: [drakelist] TR-7 Receiver Noise Date: Tue, 07 Dec 2004 16:04:27 + [EMAIL PROTECTED] made an utterence to the drakelist gang -- Greetings. I recently put a TR-7 on the air that I purchased several months ago. All is fine except that there is what I can best describe as a low frequency rumble noise that is most noticable when using headphones. It is very audible even with the RF gain set to max and the audio gain set to min. I have listed with another receiver and do not hear this noise, so I don't think I have any interference in the shack. When tuning in signals, there does not appear to be any distortion, but the background noise is very noticable. Any suggestions greatly appreciated. Vic K5TAG -- On Behalf of [EMAIL PROTECTED] Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ -- _ MSN Zoeken, voor duidelijke zoekresultaten! http://search.msn.nl -- On Behalf of Carel, PA0CMU [EMAIL PROTECTED] Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] TR-7 Receiver Noise
Carel, PA0CMU [EMAIL PROTECTED] made an utterence to the drakelist gang -- Vic, Try this: - disconnect the AC-line! - remove the PS7 control cable on the rear panel of the TR7 - make a temporary connection with a piece of wire between pins 1 and 2 of the PS7 control cable connector. The PS7 is switched to ON mode now. - carefully connect the AC power - the TR7 is switched ON too, but without the AC current through the wires in the rig. - don't use transmit mode because the fan doesn't work either! - listen to the noise you heard before. If it's gone now, the AC wiring in the TR7 is the reason of your unwished signal. Good luck, be carefull, AC power lines are dangerous. Here in the Netherlands we even have 230V. Carel - PA0CMU. _ Nieuw: Hotmail Medium, Large, Extra Large en Extra Extra Large http://join.msn.com/?pgmarket=nl-nlpage=hotmail/es2 -- On Behalf of Carel, PA0CMU [EMAIL PROTECTED] Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
RE: [drakelist] TR-7 Receiver Noise
sebdesn [EMAIL PROTECTED] made an utterence to the drakelist gang -- BE CAREFUL OF THE JUMPER ON THE CONTROL CABLE IT IS LINE VOLTAGE!!! Bud Schieving WØHG Try this: - disconnect the AC-line! - remove the PS7 control cable on the rear panel of the TR7 - make a temporary connection with a piece of wire between pins 1 and 2 of the PS7 control cable connector. The PS7 is switched to ON mode now. - carefully connect the AC power -- On Behalf of sebdesn [EMAIL PROTECTED] Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
[drakelist] TR-7 Receiver Noise
[EMAIL PROTECTED] made an utterence to the drakelist gang -- Greetings. I recently put a TR-7 on the air that I purchased several months ago. All is fine except that there is what I can best describe as a low frequency rumble noise that is most noticable when using headphones. It is very audible even with the RF gain set to max and the audio gain set to min. I have listed with another receiver and do not hear this noise, so I don't think I have any interference in the shack. When tuning in signals, there does not appear to be any distortion, but the background noise is very noticable. Any suggestions greatly appreciated. Vic K5TAG -- On Behalf of [EMAIL PROTECTED] Submissions:[EMAIL PROTECTED] Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: http://www.zerobeat.net Brought to you courtesy of TLCHost.net http://www.tlchost.net/ --
