Bonkventures‎ > ‎

TMN-1 mods to 23cm

So I finally got my hands on a Nokia TMN-1 900Mhz NMT phone. 

The hero of the story:
The vic..Hero of the story!

It indeed is the genuine article!

The unmodified insides of the phone.

902MHz PA filter jumpered crudely.
coax would be better

TX and RX VCO's before modification.

Original 900MHz duplexer removed from the left.

The handset with the screen cover removed, exposing the screws.

Handset carefully opened up, the EPROM removed for reprogramming.

EPROM closeup, this time it has the hamsoft on it.

Mainboard with the EPROM replaced with one that has the hamsoft.

weird angle

Successfully running the hamsoft!

Original PA hybrid removed.

PA candidate. This is a 900MHz amplifier removed from a NMT900 hanheld.

How the newold PA would fit in.

dremel to the rescue!

I'm yet to make a proper power cable for it.

At this point no work has been done.
Next up is removing the 900MHz duplexer, removing the 900MHz isolator after the PA and the PA hybrid. Burning the hamsoft on both the chassis and handset EPROM chips. Adding PTT support to the chassis, modifying the TX and RX VCO's to ham band. Removing the 900Mhz band filters. Inserting a 1296MHz band filter, building a working T/R relay circuit, building a working low pass filter for the PA, optimizing the RX mixer and changing the antenna connector from TNC to BNC or just buying a TNC-SMA adapter. 

Oh yeah, and making a qso with the thing!  

Picture dump of the process: