Icom Mode and Repair
Audio Mode: I am the guy who figured out why the Icom R71a Radio sounds so bad! Several companies have sold MOD kits. Others took in the radio and replaced the caps with polystyrene capacitors. I used the scientific method. I sent a high quality signal through the audio section using a MP3 play and following it along. The whole time I was posting my results over on a Icom 71a group. Oh I wish you could have been there! All the big mouths spouting about their tests and what was really wrong. I found it and it is only a design error. The tone control in the radio is only 10K it sould be 50K. When you turn the tone control off it is still on! Very simple once you know the real problem!(Right!) There is a simple solution!!! You open up the top of the radio. With the front of the radio facing you, you will see the J6 connector to your right. You can see a black wire on the connector that goes through a trace and over to C73 (.1uf). Unplug the connector and press in the tiny click tab that locks the pin into the connector. The black wire will now come out. The radio will now sound clearer. The tone control will no longer work but your audio will be clearer. With the radio on you can push the pin back in and hear the difference. There will be a loud pop! As the .1 cap charges.
The killers of Icom r71a Radios!
Killer Number 1: Shipping! It's not a pretty sight to see a smashed Icom R71a. The radio needs to packed in bubble wrap and put in a box. That gets bubble wrapped and placed in a second box. The new owner of a poorly packed radio will complain of scratchy controls. The loudmouths will tell them to spray the controls. Let me tell you something right now. The controls only vary voltage to various ICs. If your Volume contol sounds scratchy when you turn it you got a bigger problem! The volume control has been wacked straight on! Even when the radio is double boxed the power supply transformer can flex the supplies PC and break some connections. They will seem like cold solder joints around the transformer and output transistor but they came from shipping. Sometimes the Legs of the power supply output transistor snap off the body of the transistor. You won't see it at first!!!The transistor is bolted to the case and the legs are soldered in the PC board. If you look closely you can see the transistor is legless! These radios then go on to be run by an external supply!
Killer Number 2: Ham radio operators!!!!!!! They transmit right next to the radio with one of their walkitalkies. The RF from these little handsets blows out the two FETS in the front end of the radio. They will tell you it can't happen. They lie! Some of them blow the grain of wheat protector bulbs and then replace it with a jumper. Then they unload the radio online. The radio is from a silent key! Or I am unable to fully test! They put 73s in their Emails. If they only blow the front end out you are lucky. A Ham sold me one radio where he unsoldered every part in the RF board except for the two blown FETS. He never put the shields back on the board or sent them to me.
Killer Number 3: The guy who tries to change the battery in the radio. He solders two wires to the memory board. He ends up breaking the traces because he solders like a monkey!
When you see a radio online for sale missing knobs it has been dropped! The knobs of a R71a just don't fall off! They split in half! The entire shaft sometimes shears off! The seller acts cool! Look at the spring loaded antenna jack on the back of the radio. The some red parts will be missing.
How do I know all this you ask? I have bought 20 Plus radios online. All have been dropped or RF fried! I got one that an old fart had engraved his CALLS, Name and SS number all over the case. After I bid and won the radio he started asking me for more money. I felt bad for the guy until the radio arrived. He made sure his handywork did not show up in the pictures. Old and sneaky!
After a major flood or storm water damaged R71a radios show up in mass! They put them on E-dumpster. They use the words: It powers up, unable to test! Or It belonged to a family friend who recently passed away. I am selling it for his widow. The real truth is I was testing my rig "One Two One Two" when I heard a pop noise. I don't know my ass from a hole in the ground so I am unloading the radio on E-dumpster. I had my house flood! The insurance company paid me for the radio. Now I am selling it on E-dumpster. I dried the radio out and I put a drier strip in the box so you won't smell the mold! LOL
John Conrad Kleinbauer
H ome I nfo P lans O rder L inks P ics