[AMRadio] Heath HO 10 Monitor Scope
Have replaced bad 3RP1 cathode tube in my HO 10 and tested all other tubes. Have changed the two [EMAIL PROTECTED] capacitors. It is working however not up to PAR. All controls work. The current problem is that when in the trapezoid pattern monitoring AM transmitted signal, the horizontal width of the trapezoid doesn't completely fill out to a symetrical point. The horizontal position and horizontal gain pots work except that there doesn't seem to be enough horizontal gain to cause the trapezoid to fully display the full signal. I have a properly working SB 610 that shows clearly my transmitted AM signal. The HO 10 doesn't fill out the trapezoid symetrically to a point. I suspect a resistor in the horizontal gain circuit having changed value or maybe a suspect capacitor. Are there any commonly known culprits that cause this loss of horizontal gain? Naturally, I am lazy by nature, and would rather pick your brains than use my feeble brain. What are your thoughts based on your vast knowledge and EXPERIENCE??? Thanks and 73, John, K5PGW Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Heath HO 10 Monitor Scope
For starters, check the resistors in the cathode and plate circuit of the 6C10 Horizontal amp. section. Try a new 6C10. Check the input (2 mfd) and output (.22 mfd) caps for leakage. You might also check the 6BN8 RF Demodulator section and components. Pete, wa2cwa http://www.manualman.com On Sun, 24 Feb 2008 10:11:07 -0800 (PST) John King [EMAIL PROTECTED] writes: Have replaced bad 3RP1 cathode tube in my HO 10 and tested all other tubes. Have changed the two [EMAIL PROTECTED] capacitors. It is working however not up to PAR. All controls work. The current problem is that when in the trapezoid pattern monitoring AM transmitted signal, the horizontal width of the trapezoid doesn't completely fill out to a symetrical point. The horizontal position and horizontal gain pots work except that there doesn't seem to be enough horizontal gain to cause the trapezoid to fully display the full signal. I have a properly working SB 610 that shows clearly my transmitted AM signal. The HO 10 doesn't fill out the trapezoid symetrically to a point. I suspect a resistor in the horizontal gain circuit having changed value or maybe a suspect capacitor. Are there any commonly known culprits that cause this loss of horizontal gain? Naturally, I am lazy by nature, and would rather pick your brains than use my feeble brain. What are your thoughts based on your vast knowledge and EXPERIENCE??? Thanks and 73, John, K5PGW __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Heath HO 10 Monitor Scope
John, perhaps this copied email I saved will help you and others repairing the Heathkit scopes. Perhaps some of this can helpApplies to SB-6510 and HO-10 73, Larry KC8JX Owner of a SB-610 and two HO-10's *** March 14, 2007: By carl lowry [EMAIL PROTECTED] I redo the SB-610s everyday. Infact there are 8 of them in my workshop right now to be restored. The 610s were manufactured by Heathkit between 1968 and 1972. They are older than some of our recent Hams.. but many of us broke our teeth on Heathkit. Every 610 I get in here I replace all the resistors and all the caps. It takes me about 15 hours to undo replace all the components. When the Control Pots are stiff or frozen you've got to disassemble them clean them up relub. The Selenium Rectifiers I replace with 1N4007 Diodes. I have really not found any resistors or caps in the units to spec at what they originally were when first manufactured. After all they are 35 years vintage. We all change after those many years. The lack of trace wave width (TWW) can be contributed to the .05mfd cap going to pin 3 on Horizonal Gain Pot which is a 1 megohm. Also look at the Horizonal Position Pot circuit which has a .1mfd cap on pin 3. Like one of the other guys mentioned Look at the Intensity circuit. Also look at the Focus Pot next to it. I would replace the 2 Caps and the 3 resistors ( 330k 3.3m ). If you need the Mouser Part Numbers please e-mail me I will be glad to Fax you all the Mouser part numbers. Good luck. Carl. ** --- John King [EMAIL PROTECTED] wrote: Have replaced bad 3RP1 cathode tube in my HO 10 and tested all other tubes. Have changed the two [EMAIL PROTECTED] capacitors. It is working however not up to PAR. All controls work. The current problem is that when in the trapezoid pattern monitoring AM transmitted signal, the horizontal width of the trapezoid doesn't completely fill out to a symetrical point. The horizontal position and horizontal gain pots work except that there doesn't seem to be enough horizontal gain to cause the trapezoid to fully display the full signal. I have a properly working SB 610 that shows clearly my transmitted AM signal. The HO 10 doesn't fill out the trapezoid symetrically to a point. I suspect a resistor in the horizontal gain circuit having changed value or maybe a suspect capacitor. Are there any commonly known culprits that cause this loss of horizontal gain? Naturally, I am lazy by nature, and would rather pick your brains than use my feeble brain. What are your thoughts based on your vast knowledge and EXPERIENCE??? Thanks and 73, John, K5PGW Looking for last minute shopping deals? Find them fast with Yahoo! Search. http://tools.search.yahoo.com/newsearch/category.php?category=shopping __ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
