IC-V8000
 

TX from 136 to 174 MHz
The IC-V8000 has a receive frequency range from 136 MHz to 174 MHz and a transmit range of 144 MHz to 148 MHz.

The transmit circuitry can be modified to transmit from 136 MHz to 174 MHz. This requires the removal of a surface mount diode D13 from the Logic Board.


 

Expanding Function for the IC-V8000
 

Expanding Function for the IC-V8000

Icom V-8000 tx audio
Easy-to-do mod to improve tx audio dramatically!

In addition to my mod from 17-12-2002 here's the ultimate way to improve tx audio

Problem: tx audio sounds muffled and is not loud enough. Reason is too less mic amplification and therefore too less average fm deviation and too much low pass effect in the mic amp stages.

Background: The mic signal is amplified, then af-clipped and sent through a low-pass filter (all in op-amp IC3 on logic board). The af-clipped signal is then applied to the D/A converter (IC 5 on main board), where the deviation is set depending on wide or narrow operation. There is no way of alignment provided by Icom.

Modification:

  1. Locate IC 3 and nearby C79, C50 and R103 on the pictures of the logic board and the board layout.

     
  2. Replace C79 (220p) with 68p and C50 (220p) with 150p

     
  3. Replace R 103 (150k) with 330k

     
  4. That's all!

     
  5. Effect is much more average deviation without changing max. deviation and a better frequency range.

Click to enlarge
Click to enlarge the picture.

 

IC-V8000 ANL Function
To cut down on static noise, you can gain a few extra functions in the initial set-up menu, including an Automatic Noise Limiter.(ANL)

Pretty helpful in noisey conditions.

This is on the LOGIC BOARD;in the same region as the transmit expansion.

Locate D11. DIRECTLY to the LEFT of D11,and to the RIGHT of the two diodes to open up the transmit, (rite in between)is R54.

Remove or desolder and lift one end.

Re-assemble and reset cpu. You now have access to the Automatic Noise Limiter, as well as a few more functions; although, I have not as yet figured out what the other functions are; exactly.

Be careful,R54 is NOT in the same white-cuped patch as the diodes for opening up the transmit. It is immediately to the right of the white cups; and immediately to the left of D11, kind of in-line with the lower row of cups.

Good luck, and enjoy! Mike
KG6FPC

 

Icom V-8000 TX-audio
TX audio is not loud enough, i.e. average fm deviation is too low. There is no conventional way to align it, because the V-8000 has no pot to adjust fm deviation.

Solution:
First, you can increase the hole in the mic and esp. The hole of the plastic keypad inside the mic as K8DXN describes. But that is not enough.
FM deviation is set in IC 5, an 8-bit D/A converter. Because no software alignment is possible I decided to insert a pot to set the deviation.

  1. Find IC 5=M62363, 24pin smd D/A converter (see picture)

     
  2. Solder off pin 1 and pin 2

     
  3. Solder a 100k pot on jumper 2 (J2 in the picture), one end to pin 2 and the other at pin 6 (ground)

     
  4. Solder the free end of the pot to the place where pin 2 of IC 5 was soldered on the board (pin 2 now soldered off)

     
  5. Connect free pin 1 of IC 5 with pin 12 of IC 5

     
  6. Adjust fm dev with the 100 k pot

     
  7. There is no more difference in fm dev between wide and narrow operation.

73 from Erwin, DF4CL

 

V8000 gne caper
V8000 mod for general coverage tx (makes a good marine tx.er)

On the front panel there are 4 diodes side by side they have white cups drawn around them remove all and of you go(go baby go). The diodes are on the top of the pcb very clandestine looking ones the unit will produce at least 31 watts on the marine band

bye form spritsan.

Thanks to Charlie M - KA4CMT for this picture.
               

            

 

ATTENTION
The KB2LJJ takes no responsibility for any damage during the modification or for any wrong information made on this modification.