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IC-7000 on 4m (70MHz)?


David Sadler-Lockwood
 

The four metre band here in the UK is undergoing a massive growth of activity.
Has anyone successfully modified an IC-7000 to cover that band?

73 es TIA

Dave G4CLI


Greg Stramback
 

I would think, even if the logic allowed that band to exist (i.e., the controller is used in other ICOM products) that the RF board would be missing the filters / guts for this. 


This discussion on 70MHz.org touches on this, and points toward the 7100 possibly being first to have it, but not the 7000.

-greg-
KD6VEN

On Mar 30, 2020, at 07:13, David Sadler-Lockwood <davidg4cli@...> wrote:

The four metre band here in the UK is undergoing a massive growth of activity.
Has anyone successfully modified an IC-7000 to cover that band?

73 es TIA

Dave G4CLI


Roeland Jansen, PA3MET
 

I do have a working example of a 4m TX-able 7000 with an external PA that also filters garbage (2x70MHz). The latter is needed as the internal filtering has been 
modified to pass on TX. I did not modify it myself though.

 

I'll see if I can find back the article of the guy who did it -- else I can start searching a stack of papers where the mod was documented. Somewhere here...

 

 


Roeland Jansen, PA3MET
 

the TRX belonged to Richard, PA7FA -- Found back parts of the info here too:

http://www.70mhz.org/forum/viewtopic.php?f=6&t=452&hilit=7000

 

I removed C26 and C32 on the main board of the IC7000. This increased the output @ 70 MHz with 10 dB.
This was enough to drive a amplifier i build using a hybrid module from Mitsubishi (RA30H0608M) available from Grant Engineering (http://www.ghengineering.co.uk/) for 32.50 pounds. At the input stage of the amplifier i builded a sharp band pass filter. The residual 140 Mhz and 210 Mhz from the Rig are terminated with 50 ohm, and the 70 MHz is passed into the amp. I get approx 40Watt clean SSB/CW @ 70 MHz from the amp this way, and the Icom stays happy.

Removing the 2 capacitors is not for the faint hearted. The C's are 0.8 mm in length, and hard to find. I have a microscope, and a micro SMD rework station. SMD is my daily bussiness.....

I realize the method described is not the nicest. The problem is to replace the existing filter with a filter which passes 145 AND 70 MHz. I am not able to design this, and ended up this way, by modifiying the existting filter, and terminating the residual unwanted signals in the amplifier.

Good luck!

 

(that was written by Richard)

 

And I happen to have that IC7000 and PA on the desk here.