Yaesu FT-7800 TX Expansion Mod.
I found one youtube video on this. I found 3 text articles that were confusing at best. So here we are like 11 years after my ever popular Yaesu FT-840 power resistor fix so you dont blow your radio up by just using it. I love the Amateur radio community because in the past 20 years Ive been able to find everything I am looking for because people take time to write it up. When I come across something not documented fully I dont mind writing it up.
Enough nonsense, I bring to you. The Yaesu Ft-7800 TX Expansion Mod.
Here is the directions I followed off a GREAT Romanian site. http://motorola.dmz.ro/yaesu/ft-7800r-tx-mod.php
These are great. I think they are a bit technical and may scare away people who might otherwise try this. Anyhow, I like it to be idiot proof and easy so here is my attempt at writing this up. If this helps you send me a comment at the bottom. I love reading success stories and it means me writing this up wasnt a complete waste of time.
Here goes.
The Yaesu FT-7800 TX Expansion modification.
1. Remove the top cover, by unscrewing the 8 screws (4 on the sides 4 on the top) holding the case on.(marked in blue)
Do NOT pull the four screws out for the speaker. (marked in RED) it isnt necessiary and the speaker will fall onto the PCB I guess.
3. Remove the cover and disconnect the speaker. It just pulls straight out of the PCB.
4. ok now it is time to find the soldered in diode on the pcb. You will be removing that with a solder iron.
You can see the surface mount diode (I dont actually know if it a diode or not. Ive never had any formal electronics training.I went to a college prep high school that didnt give us any kind of classes like this.)
You need to remove it. See the yellow circle. It is soldered to two points on the board. You are going to need a fine tip soldering iron. I think it is a great investment to get a 50 dollar soldering iron where you can control the heat. 400 degrees F seems to work for me thus far (If that isnt right I am sure the internet will tell me - lol)
You are going to need to put heat on both sides of the part. It will just come loose eventually. It isnt like it is between two pins. (I was wondering if I needed my xacto blade knife to move it once I got it loose. I didnt. It flew away. Never to be seen again or it was that tiny black dot I saw on my soldering iron. Not sure but after I applied about 15 seconds to a side it came loose.
Anyhow Here is what it looks like gone. You can see it is a little rough because it took a lot longer to get it to warm up enough to remove it. You can also see I hit the pins just to the right of it.
There you go. after you apply power it reboots.. clears all the memories and it will xmit in the expanded ranges.
GMRS Channel 1 with 4Watts into my multiband Base station Antenna.
