Yes, that fuse is your first thing to check. Even a nanosecond short on the 12v rail will instantly take out that fuse. They can also fail from years of stress, or there could be oxidation on the fuse holder. It's not quite as hard to change as that, but it does require some dexterity. I usually pop it out with a screwdriver or needlenose pliers (whatever's handy) and let it fall to the bottom of the rig, then turn the rig over. Disconnect the external power supply from the radio first, use an exact replacement only (do not overfuse!), and don't bump those pesky passband adjustment pots on the power supply board.
If the new fuse blows, you have a problem elsewhere. 73 -Jim NU0C On Sun, 20 May 2012 18:47:42 +1000, Eraina & Richard Jenkins wrote: >My TR-7 is completely dead. I've carefully checked the power >supply ... and the problem is not there. 13.5 volts is getting through >to the rig. No lights or display come on or anything. No sound from >the speaker. Reading Ronald's (WB4HFN) article on "Inside the Drake >TR-7 transceiver", he suggests that I try the 5 amp fuse which is >underneath the top cover on the rig at the front. Replacement is >possible for the double-jointed it seems. It is located almost >underneath the digital display board. > >Does this fuse fail frequently? Is it a slow-blo type ... or just a >regular auto-type fuse (3AG)? Is there anything to be gained by upping >it to 7.5A or even 10A? > > >Many thanks for your help > >73 > >Richard >VK1RJ > > >-- >-- >Eraina & Richard Jenkins >Canberra >'richardirena' on skype ... if at home ... >+++++++++++++++++++++++++++++++++++++++++ > >_______________________________________________ >Drakelist mailing list >Drakelist@zerobeat.net >http://mailman.zerobeat.net/mailman/listinfo/drakelist -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! "Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime." HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org _______________________________________________ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
