From cbfsb!att!linac!uwm.edu!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!athena.cs.uga.edu!mcovingt Sun Apr 5 16:26:04 EDT 1992 Article: 17074 of rec.radio.amateur.misc Xref: cbfsb rec.radio.shortwave:14875 sci.electronics:27585 rec.radio.amateur.misc:17074 Path: cbfsb!att!linac!uwm.edu!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!athena.cs.uga.edu!mcovingt From: mcovingt@athena.cs.uga.edu (Michael A. Covington) Newsgroups: rec.radio.shortwave,sci.electronics,rec.radio.amateur.misc Subject: How to detect and fix common Sony 2010 problem Summary: Fried JFET easily replaced with Radio Shack MPF102 Message-ID: <1992Apr4.184635.17406@athena.cs.uga.edu> Date: 4 Apr 92 18:46:35 GMT References: <1992Apr1.151210.1131@ciit85.ciit.nrc.ca> <10190011@hpuerca.atl.hp.com> <1992Apr4.171730.9192@athena.cs.uga.edu> Organization: University of Georgia, Athens Lines: 76 HOW TO DETECT AND REPAIR THE COMMONLY BLOWN TRANSISTOR IN THE SONY 2010 Michael Covington, N4TMI (Free distribution; you are welcome to copy and distribute this document.) As is well known, transistor Q303 in the front-end of the Sony ICF-2010 general coverage receiver is easily damaged by static electricity. Here is information on how to diagnose and fix this problem. WHAT ARE THE SYMPTOMS? A 10- to 20-dB loss of sensitivity on AM (longwave, medium wave, short wave). If you have a good antenna you may not even notice the loss. In all other respects the radio functions normally. HOW DO I TEST IT? If you buy a used 2010 it's a good idea to perform this test even if you do not notice a performance problem. Remove the back cover and locate transistor Q303, near the antenna input. Identify its three terminals (D, G, and S). Now measure the voltage from each of those terminals to ground, with the receiver turned on and receiving shortwave. (A convenient ground connec- tion is the outer part of the antenna jack.) The voltages should be: S 0.2V G 0.0 V D 2.9 V Note especially the drain (D) voltage. If it is substantially lower than 2.9V, the transistor is leaky. (Mine measured 1.6V when defective.) If it's substantially higher (like 4.5V), the transistor is open. HOW DO I FIX IT? The popular MPF-102 transistor, available at Radio Shack, is a suitable replacement. (Sony used a 2SK152, not widely available in the U.S.A.) Simply unsolder the old transistor and install the new one, then check voltages again. No alignment is necessary. HOW DO I PREVENT FURTHER TROUBLE? By connecting the shortwave antenna through a protective diode network, as shown below. \|/ Antenna | +-----------+--------+----------------------------> tip of plug | | \ / --- Sony 2010 --- / \ Four 1N914 or antenna | | 1N4148 diodes jack \ / --- (do not substitute) --- / \ | | +-----------+--------+----------------------------> sleeve of plug | ------- ----- --- Ground (optional) The diodes limit all voltages going into the receiver. Use the specified types; other kinds would produce loss of signal, signal mixing (resulting in image frequencies), or both. The 2010 has a built-in protective diode network connected to the built-in telescoping antenna but not the antenna jack. -- ========================================================================== Michael A. Covington, Ph.D. | mcovingt@uga.cc.uga.edu | ham radio N4TMI Artificial Intelligence Programs | U of Georgia | Athens, GA 30602 U.S.A. ========================================================================== Article: 17202 of rec.radio.shortwave Path: news.cs.tut.fi!news.funet.fi!sunic!lunic!eru.mt.luth.se!enterpoop.mit.edu!spool.mu.edu!agate!iat.holonet.net!psinntp!psinntp!panix!schuster From: schuster@panix.com (Michael Schuster) Newsgroups: rec.radio.shortwave Subject: ICF-2010 adjustment revisited Message-ID: Date: 10 Jan 93 13:16:33 GMT Organization: Panix Public Access Internet & Unix, NYC Lines: 104 The following is re-posted from the Fidonet shortwave echo: 01/05/93 15:08:00 From: GREG HORODECK To: BILL OXNER Subj: SONY 2010 FREQUENCY ADJUSTMENT I have a Service Manual for the Sony ICF-2010 and the alignment procedure forwarded by you from Genie is partially correct and I am amazed how the original author stumbled into it just by looking at the radio. Following is the instructions taken from the manual, which leave something to be desired, since pictures of the actual circuit board are part of the procedure and are important for identifying the adjustment points. Sync Adjustment Note: Frequency setting may alter when adjusted with shield plate (K) removed from sync board. Setup: Band: AM Mode: as directed AM RF GAIN Control: as adequate Frequency: as directed MANUAL TUNE MODE: SLOW SYNC switch: as directed Remove shield plate (K) and connect a test lead to pin 6 (varicap voltage) for VTVM and frequency counter and reinstall shield plate (K). (There is a picture of a PC board trace with arrows where to attach the VTVM, Frequency counter, and Oscilliscope which defy any way of being described here. There are three adjusting points; CT601 (a variable cap) which is located through a small hole in the shielded SYNC unit itself, VT1 (a pot) which is located directly next to the shielded SYNC unit on the right, and VT2 a pot) which is on the left of the shielded SYNC unit near the corner of the printed circuit board.) Procedure: 1. Correctly and just tune in the set to a known, stable and strong AM station in NARROW and SYNC MODE off modes. 2. Set mode to USB. 3. Adjust VT1 for a 1.5V DC VTVM reading. 4. Adjust CT601 for a zero-beat note and waveform. (There is a picture of the proper and improper oscilliscope waveforms.) 5. Turn SYNC switch on and, adjust VT2 and set it to the point at which SYNC LOWER indicator just turns off to SYNC UPPER indication. Slowly turn VT2 back to the point at which SYNC UPPER indicator just turns off to SYNC LOWER indication, and leave VT2 as is. 6. Turn MANUAL TUNING knob to obtain a frequency indication just 100 Hz above the carrier of the station being received. (only one advancement in the final digit). Now, the SYNC UPPER indicator should light. 7. Frequency counter should read 3.640 MHz + or - 100 Hz. Refer to the original message from Gary Pupurs on Genie as forwarded to this echo by Bill Oxner for a description on how to open, precautions to take, and how to identify the SYNC unit. Since my display is spot on, I did not open up the radio to verify the colors of the pots. The service manual is quite comprehensive and includes the owners manual instructions, disassembly instructions, adjustments and alignment procedures, voltage testpoint tables, sample waveform patterns, mounting diagram (ghost of PC board and components), schematic diagram, and parts list. It can be ordered by calling 816/891-7550 and going through the automated voices to publications. Cost was around $10 when I got mine three years and they do charge $3 for shipping and take plastic. As Gary Pupurs warned, fooling around without a Service Manual is not for the faint hearted and a trip to the Sony Service Repair Center will most certainly be more costly than the Manual. I order a Service Manual as soon as I acquire any consumer electric item and they have certainly paid off. Greg --- * Origin: The Emporium BBS HST/V32/V42 708-551-9275 (1:115/551) -- _______________________________Mike Schuster________________________________ NY Pub. Access UNIX/Internet: schuster@panix.com | 70346.1745@CompuServe.COM The Portal (R) System: schuster@shell.portal.com | MCI Mail,GEnie: MSCHUSTER From cbfsb!att!pacbell.com!ames!elroy.jpl.nasa.gov!usc!wupost!uunet!gsm001!gsm Fri Jan 31 10:29:59 EST 1992 Article: 13165 of rec.radio.shortwave Newsgroups: rec.radio.shortwave Path: cbfsb!att!pacbell.com!ames!elroy.jpl.nasa.gov!usc!wupost!uunet!gsm001!gsm From: gsm@mendelson.com (Geoffrey S. Mendelson) Subject: How to reapir your 2010 (reprint) Message-ID: <1992Jan31.022116.1878@mendelson.com> Organization: Mendelson Computer Consulting Date: Fri, 31 Jan 92 02:21:16 GMT The following was posted on 12 Dec 1991 by: nash@ucselx.sdsu.edu (Ron Nash) In article jpd@presto.ig.com.UUCP (Jean-Pierre Dautricourt) writes: >In article <91345.075622AMELMN02@ysub.ysu.edu> AMELMN02@ysub.ysu.edu writes: >>If a 2010 has been attached to a long wire or other bigger outside antenna >>it may have received TOO much signal. There is no protection of the FETs in >>the front end. There are three and when the first one goes you think >>performance is down so you try and feed it more signal. When the second one >>goes the radio becomes VERY deaf. Sony added that external antenna jack as >>an after thought. There is no diode to protect it from signals that are too >>strong. The whip does have a protection diode. End of my input... > >Is there a way to test if any of the FET's are out (besides just suspecting >some performance loss)? Here is how to test and fix your 2010 from my moldy archives. Subject: How I Fixed My Sony 2010 Summary: How to replace FET that commonly fails. Keywords: Sony 2010 shortwave receiver sensitivity FET Message-ID: <1991Jul15.044316.2141@athena.cs.uga.edu> Date: 15 Jul 91 04:43:16 GMT Organization: University of Georgia, Athens (Somebody please save this in an archive somewhere... it's a frequently asked question.) The most common component failure in the Sony ICF-2010 (ICF-2001D) receiver is probably Q303, the AM front end transistor. The symptom is loss of sensitivity (either sudden, or gradual and insidious). In previous net discussion people have said that the failure is due to static electricity, but mine went kaput while I was using an antenna well protected by diodes. Personally, I suspect Sony got a bad batch of transistors. Anyhow, the repair is easy and does not involve any adjustments or alignment. Here is the procedure: (1) Remove the back cover by removing the 7 screws that are marked with arrows. (One is inside the battery compartment.) Leave the computer batteries in place. (2) Locate Q303, which is well marked on the small circuit board near the antenna jack. The terminals are G(ate), S(ource), and D(rain), in that order. G is marked. (3) If you care to make a test, operate the radio in AM mode and measure the voltage from the drain of Q303, to the sleeve of the antenna jack (which is circuit ground). If substantially below 2.9V it indicates that Q303 is leaky. (4) Replace Q303 with the readily available MPF102 or any other low-noise N-channel JFET, making sure to get D, S, and G connected correctly. (5) That's all; put the radio back together and evaluate sensitivity. 73 de N4TMI -- ------------------------------------------------------- Michael A. Covington | Artificial Intelligence Programs The University of Georgia | Athens, GA 30602 U.S.A. ------------------------------------------------------- -- Copyright (C) 1992, Geoffrey S. Mendelson. All Rights Reserved. Except for usenet followups, may not be reproduced without permsission. ---------------------------------------------------------------------------- | | Computer Software Consulting | | ---------------------------------------------------------------------------- Geoffrey S. Mendelson Israel geoffrey@mendelson.com or mwcbbs!mailgsm!geoffrey Bust! (215) 242-8712 Looks like August now :-( From cbfsb!att!emory!athena.cs.uga.edu!mcovingt Mon Jul 15 15:45:45 EDT 1991 Article: 8311 of rec.radio.shortwave Xref: cbfsb rec.radio.shortwave:8311 sci.electronics:17778 Path: cbfsb!att!emory!athena.cs.uga.edu!mcovingt From: mcovingt@athena.cs.uga.edu (Michael A. Covington) Newsgroups: rec.radio.shortwave,sci.electronics Subject: How I Fixed My Sony 2010 Summary: How to replace FET that commonly fails. Keywords: Sony 2010 shortwave receiver sensitivity FET Message-ID: <1991Jul15.044316.2141@athena.cs.uga.edu> Date: 15 Jul 91 04:43:16 GMT Organization: University of Georgia, Athens Lines: 43 (Somebody please save this in an archive somewhere... it's a frequently asked question.) The most common component failure in the Sony ICF-2010 (ICF-2001D) receiver is probably Q303, the AM front end transistor. The symptom is loss of sensitivity (either sudden, or gradual and insidious). In previous net discussion people have said that the failure is due to static electricity, but mine went kaput while I was using an antenna well protected by diodes. Personally, I suspect Sony got a bad batch of transistors. Anyhow, the repair is easy and does not involve any adjustments or alignment. Here is the procedure: (1) Remove the back cover by removing the 7 screws that are marked with arrows. (One is inside the battery compartment.) Leave the computer batteries in place. (2) Locate Q303, which is well marked on the small circuit board near the antenna jack. The terminals are G(ate), S(ource), and D(rain), in that order. G is marked. (3) If you care to make a test, operate the radio in AM mode and measure the voltage from the drain of Q303, to the sleeve of the antenna jack (which is circuit ground). If substantially below 2.9V it indicates that Q303 is leaky. (4) Replace Q303 with the readily available MPF102 or any other low-noise N-channel JFET, making sure to get D, S, and G connected correctly. (5) That's all; put the radio back together and evaluate sensitivity. 73 de N4TMI -- ------------------------------------------------------- Michael A. Covington | Artificial Intelligence Programs The University of Georgia | Athens, GA 30602 U.S.A. ------------------------------------------------------- From cbfsb!att!linac!uwm.edu!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!athena.cs.uga.edu!mcovingt Sun Apr 5 16:26:04 EDT 1992 Article: 17074 of rec.radio.amateur.misc Xref: cbfsb rec.radio.shortwave:14875 sci.electronics:27585 rec.radio.amateur.misc:17074 Path: cbfsb!att!linac!uwm.edu!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!emory!athena.cs.uga.edu!mcovingt From: mcovingt@athena.cs.uga.edu (Michael A. Covington) Newsgroups: rec.radio.shortwave,sci.electronics,rec.radio.amateur.misc Subject: How to detect and fix common Sony 2010 problem Summary: Fried JFET easily replaced with Radio Shack MPF102 Message-ID: <1992Apr4.184635.17406@athena.cs.uga.edu> Date: 4 Apr 92 18:46:35 GMT References: <1992Apr1.151210.1131@ciit85.ciit.nrc.ca> <10190011@hpuerca.atl.hp.com> <1992Apr4.171730.9192@athena.cs.uga.edu> Organization: University of Georgia, Athens Lines: 76 HOW TO DETECT AND REPAIR THE COMMONLY BLOWN TRANSISTOR IN THE SONY 2010 Michael Covington, N4TMI (Free distribution; you are welcome to copy and distribute this document.) As is well known, transistor Q303 in the front-end of the Sony ICF-2010 general coverage receiver is easily damaged by static electricity. Here is information on how to diagnose and fix this problem. WHAT ARE THE SYMPTOMS? A 10- to 20-dB loss of sensitivity on AM (longwave, medium wave, short wave). If you have a good antenna you may not even notice the loss. In all other respects the radio functions normally. HOW DO I TEST IT? If you buy a used 2010 it's a good idea to perform this test even if you do not notice a performance problem. Remove the back cover and locate transistor Q303, near the antenna input. Identify its three terminals (D, G, and S). Now measure the voltage from each of those terminals to ground, with the receiver turned on and receiving shortwave. (A convenient ground connec- tion is the outer part of the antenna jack.) The voltages should be: S 0.2V G 0.0 V D 2.9 V Note especially the drain (D) voltage. If it is substantially lower than 2.9V, the transistor is leaky. (Mine measured 1.6V when defective.) If it's substantially higher (like 4.5V), the transistor is open. HOW DO I FIX IT? The popular MPF-102 transistor, available at Radio Shack, is a suitable replacement. (Sony used a 2SK152, not widely available in the U.S.A.) Simply unsolder the old transistor and install the new one, then check voltages again. No alignment is necessary. HOW DO I PREVENT FURTHER TROUBLE? By connecting the shortwave antenna through a protective diode network, as shown below. \|/ Antenna | +-----------+--------+----------------------------> tip of plug | | \ / --- Sony 2010 --- / \ Four 1N914 or antenna | | 1N4148 diodes jack \ / --- (do not substitute) --- / \ | | +-----------+--------+----------------------------> sleeve of plug | ------- ----- --- Ground (optional) The diodes limit all voltages going into the receiver. Use the specified types; other kinds would produce loss of signal, signal mixing (resulting in image frequencies), or both. The 2010 has a built-in protective diode network connected to the built-in telescoping antenna but not the antenna jack. -- ========================================================================== Michael A. Covington, Ph.D. | mcovingt@uga.cc.uga.edu | ham radio N4TMI Artificial Intelligence Programs | U of Georgia | Athens, GA 30602 U.S.A. ========================================================================== Article: 17202 of rec.radio.shortwave Path: news.cs.tut.fi!news.funet.fi!sunic!lunic!eru.mt.luth.se!enterpoop.mit.edu!spool.mu.edu!agate!iat.holonet.net!psinntp!psinntp!panix!schuster From: schuster@panix.com (Michael Schuster) Newsgroups: rec.radio.shortwave Subject: ICF-2010 adjustment revisited Message-ID: Date: 10 Jan 93 13:16:33 GMT Organization: Panix Public Access Internet & Unix, NYC Lines: 104 The following is re-posted from the Fidonet shortwave echo: 01/05/93 15:08:00 From: GREG HORODECK To: BILL OXNER Subj: SONY 2010 FREQUENCY ADJUSTMENT I have a Service Manual for the Sony ICF-2010 and the alignment procedure forwarded by you from Genie is partially correct and I am amazed how the original author stumbled into it just by looking at the radio. Following is the instructions taken from the manual, which leave something to be desired, since pictures of the actual circuit board are part of the procedure and are important for identifying the adjustment points. Sync Adjustment Note: Frequency setting may alter when adjusted with shield plate (K) removed from sync board. Setup: Band: AM Mode: as directed AM RF GAIN Control: as adequate Frequency: as directed MANUAL TUNE MODE: SLOW SYNC switch: as directed Remove shield plate (K) and connect a test lead to pin 6 (varicap voltage) for VTVM and frequency counter and reinstall shield plate (K). (There is a picture of a PC board trace with arrows where to attach the VTVM, Frequency counter, and Oscilliscope which defy any way of being described here. There are three adjusting points; CT601 (a variable cap) which is located through a small hole in the shielded SYNC unit itself, VT1 (a pot) which is located directly next to the shielded SYNC unit on the right, and VT2 a pot) which is on the left of the shielded SYNC unit near the corner of the printed circuit board.) Procedure: 1. Correctly and just tune in the set to a known, stable and strong AM station in NARROW and SYNC MODE off modes. 2. Set mode to USB. 3. Adjust VT1 for a 1.5V DC VTVM reading. 4. Adjust CT601 for a zero-beat note and waveform. (There is a picture of the proper and improper oscilliscope waveforms.) 5. Turn SYNC switch on and, adjust VT2 and set it to the point at which SYNC LOWER indicator just turns off to SYNC UPPER indication. Slowly turn VT2 back to the point at which SYNC UPPER indicator just turns off to SYNC LOWER indication, and leave VT2 as is. 6. Turn MANUAL TUNING knob to obtain a frequency indication just 100 Hz above the carrier of the station being received. (only one advancement in the final digit). Now, the SYNC UPPER indicator should light. 7. Frequency counter should read 3.640 MHz + or - 100 Hz. Refer to the original message from Gary Pupurs on Genie as forwarded to this echo by Bill Oxner for a description on how to open, precautions to take, and how to identify the SYNC unit. Since my display is spot on, I did not open up the radio to verify the colors of the pots. The service manual is quite comprehensive and includes the owners manual instructions, disassembly instructions, adjustments and alignment procedures, voltage testpoint tables, sample waveform patterns, mounting diagram (ghost of PC board and components), schematic diagram, and parts list. It can be ordered by calling 816/891-7550 and going through the automated voices to publications. Cost was around $10 when I got mine three years and they do charge $3 for shipping and take plastic. As Gary Pupurs warned, fooling around without a Service Manual is not for the faint hearted and a trip to the Sony Service Repair Center will most certainly be more costly than the Manual. I order a Service Manual as soon as I acquire any consumer electric item and they have certainly paid off. Greg --- * Origin: The Emporium BBS HST/V32/V42 708-551-9275 (1:115/551) -- _______________________________Mike Schuster________________________________ NY Pub. Access UNIX/Internet: schuster@panix.com | 70346.1745@CompuServe.COM The Portal (R) System: schuster@shell.portal.com | MCI Mail,GEnie: MSCHUSTER From cbfsb!att!pacbell.com!ames!elroy.jpl.nasa.gov!usc!wupost!uunet!gsm001!gsm Fri Jan 31 10:29:59 EST 1992 Article: 13165 of rec.radio.shortwave Newsgroups: rec.radio.shortwave Path: cbfsb!att!pacbell.com!ames!elroy.jpl.nasa.gov!usc!wupost!uunet!gsm001!gsm From: gsm@mendelson.com (Geoffrey S. Mendelson) Subject: How to reapir your 2010 (reprint) Message-ID: <1992Jan31.022116.1878@mendelson.com> Organization: Mendelson Computer Consulting Date: Fri, 31 Jan 92 02:21:16 GMT The following was posted on 12 Dec 1991 by: nash@ucselx.sdsu.edu (Ron Nash) In article jpd@presto.ig.com.UUCP (Jean-Pierre Dautricourt) writes: >In article <91345.075622AMELMN02@ysub.ysu.edu> AMELMN02@ysub.ysu.edu writes: >>If a 2010 has been attached to a long wire or other bigger outside antenna >>it may have received TOO much signal. There is no protection of the FETs in >>the front end. There are three and when the first one goes you think >>performance is down so you try and feed it more signal. When the second one >>goes the radio becomes VERY deaf. Sony added that external antenna jack as >>an after thought. There is no diode to protect it from signals that are too >>strong. The whip does have a protection diode. End of my input... > >Is there a way to test if any of the FET's are out (besides just suspecting >some performance loss)? Here is how to test and fix your 2010 from my moldy archives. Subject: How I Fixed My Sony 2010 Summary: How to replace FET that commonly fails. Keywords: Sony 2010 shortwave receiver sensitivity FET Message-ID: <1991Jul15.044316.2141@athena.cs.uga.edu> Date: 15 Jul 91 04:43:16 GMT Organization: University of Georgia, Athens (Somebody please save this in an archive somewhere... it's a frequently asked question.) The most common component failure in the Sony ICF-2010 (ICF-2001D) receiver is probably Q303, the AM front end transistor. The symptom is loss of sensitivity (either sudden, or gradual and insidious). In previous net discussion people have said that the failure is due to static electricity, but mine went kaput while I was using an antenna well protected by diodes. Personally, I suspect Sony got a bad batch of transistors. Anyhow, the repair is easy and does not involve any adjustments or alignment. Here is the procedure: (1) Remove the back cover by removing the 7 screws that are marked with arrows. (One is inside the battery compartment.) Leave the computer batteries in place. (2) Locate Q303, which is well marked on the small circuit board near the antenna jack. The terminals are G(ate), S(ource), and D(rain), in that order. G is marked. (3) If you care to make a test, operate the radio in AM mode and measure the voltage from the drain of Q303, to the sleeve of the antenna jack (which is circuit ground). If substantially below 2.9V it indicates that Q303 is leaky. (4) Replace Q303 with the readily available MPF102 or any other low-noise N-channel JFET, making sure to get D, S, and G connected correctly. (5) That's all; put the radio back together and evaluate sensitivity. 73 de N4TMI -- ------------------------------------------------------- Michael A. Covington | Artificial Intelligence Programs The University of Georgia | Athens, GA 30602 U.S.A. ------------------------------------------------------- -- Copyright (C) 1992, Geoffrey S. Mendelson. All Rights Reserved. Except for usenet followups, may not be reproduced without permsission. ---------------------------------------------------------------------------- | | Computer Software Consulting | | ---------------------------------------------------------------------------- Geoffrey S. Mendelson Israel geoffrey@mendelson.com or mwcbbs!mailgsm!geoffrey Bust! (215) 242-8712 Looks like August now :-( From cbfsb!att!emory!athena.cs.uga.edu!mcovingt Mon Jul 15 15:45:45 EDT 1991 Article: 8311 of rec.radio.shortwave Xref: cbfsb rec.radio.shortwave:8311 sci.electronics:17778 Path: cbfsb!att!emory!athena.cs.uga.edu!mcovingt From: mcovingt@athena.cs.uga.edu (Michael A. Covington) Newsgroups: rec.radio.shortwave,sci.electronics Subject: How I Fixed My Sony 2010 Summary: How to replace FET that commonly fails. Keywords: Sony 2010 shortwave receiver sensitivity FET Message-ID: <1991Jul15.044316.2141@athena.cs.uga.edu> Date: 15 Jul 91 04:43:16 GMT Organization: University of Georgia, Athens Lines: 43 (Somebody please save this in an archive somewhere... it's a frequently asked question.) The most common component failure in the Sony ICF-2010 (ICF-2001D) receiver is probably Q303, the AM front end transistor. The symptom is loss of sensitivity (either sudden, or gradual and insidious). In previous net discussion people have said that the failure is due to static electricity, but mine went kaput while I was using an antenna well protected by diodes. Personally, I suspect Sony got a bad batch of transistors. Anyhow, the repair is easy and does not involve any adjustments or alignment. Here is the procedure: (1) Remove the back cover by removing the 7 screws that are marked with arrows. (One is inside the battery compartment.) Leave the computer batteries in place. (2) Locate Q303, which is well marked on the small circuit board near the antenna jack. The terminals are G(ate), S(ource), and D(rain), in that order. G is marked. (3) If you care to make a test, operate the radio in AM mode and measure the voltage from the drain of Q303, to the sleeve of the antenna jack (which is circuit ground). If substantially below 2.9V it indicates that Q303 is leaky. (4) Replace Q303 with the readily available MPF102 or any other low-noise N-channel JFET, making sure to get D, S, and G connected correctly. (5) That's all; put the radio back together and evaluate sensitivity. 73 de N4TMI -- ------------------------------------------------------- Michael A. Covington | Artificial Intelligence Programs The University of Georgia | Athens, GA 30602 U.S.A. -------------------------------------------------------