FRG-7 mods page

Or when a FRG-7 enter the digital age

Introduction

What is a FRG-7 ?
It's a shortwave radio recever from the 80's which was very good for the money and so was quiet popular in its time.
Its design was clever, simple with lots of place in its solid metal case. All that make it the perfect target to lots of sort of mods.
I used mine when I was a teenager and had lot of fun with it. In particular, I remenber listening to transatlantic sailing race boats during the great transatlantic races of the 80's (now they all use satellite links ...).

Since them, it was taking dust in the attic when I wonder what I could do funny with my EVM56002 DSP board :

What I could do with a 20 years old FRG-7 and a 5 years old DSP card ?
Well, some interesting things in fact, and so I enter into the infinite world of FRG-7 mods ....

The goal of this page is to list all the mods I have done to my poor old FRG-7, somes are trivial, others more complex.

In any case, as usual in any mods description, I take no responsability to any dommage you could do to anything by tring to do like me.

I even advise not to do so, because it's a pure waste of time (but really fun).

Before beginning anything, get the schematics here and take advices from the FRG-7 forum.

Mods list

More power

The power transformer of the original FRG-7 is small (normal on a low budget receiver) . The first thing I do, is to replace it by a good 20VA one. I change the internal 10V regulator too and rewired the light supply to get their power before voltage regulation :

Digital frequency Display

Yes analog frequency display is cool , but not very easy to read.I remove it and put a digital frequency display insteed.
I was lazy and just bought a kit cached and cut some hole into a plastic plate to put all that in place.
Works great but generate some birdies, I have to work on it.

Green look

FRG-7 original use small, impossible to find, light bulbs to backlight its selectors (band and tuning). Somes lights fries and I decided to replace all lighs by green leds.

Why green ? because it's the color of the digital frequency display backlight led.
So now my FRG-7 have a beautifull uniform green look ...

External speaker

The FRG-7's internal speaker sucks.

So I decided to use home made external speaker. they are largely better and it makes place for the LCD display :

Digital demodulator

So come back at the beginning of my story, what man could do with a FRG-7 and a DSP board ?
Answer : use the DSP to replace the AM/SSB demodulator.

It was my first goal and my more complex mod. I have dedicated a web page to it.
It improve AM and SSB reception, add FM demodulation and in the future add digital modes like RTTY and even spectrum display on a little graphic LCD display (I couls always promise wonderful things for the future, I have not signed anything)

To put all that in the FRG-7 I have :

put the 56002EVM board in place of the battry pack, it's just the good dimension !
put the needed analog front end on the side of the DSP card, on the vertical metal plate that is between battry pack and power transformer.
rewired completly the mode selector : The BFO is not used any more and there is no more audio source to select (the ouput of the DSP card go directly to the volume potentiometer.).
This selector is now used solely to swith on/off 2 logical input pins of the DSP, that are used by my demodulation programm to select mode.
removed the balanced modulator diodes. The input of the analog front-end is connected insteed, at the output of T405

and it works ! Here is an image of the internals :

LCD display

Yes, in the future, I will try to program a spectrum display. I have at least the LCD display in place: