Tank Radio BC-603 receiver

[Vecher1]

ALL, need to know how to remove the Push button assembly.

Thanks, Skip.

[HamishBoxer]

Just had a look at one and for starters the front panel has to come off and I would say some serious dismantling.

[Vecher1]

Yup I agree. I was able to get front panel off

Decided to not take take assembly out..

My issue is the tuning control is frozen cannot turn it at all so i thought it would be easier to work on it with assy out

Skip

[Vecher1]

Need a power supply for this .. I do not have the Dynamotor.. Any have a schematic of one??


Skip

[G3VKM_Roger]

The original manual is here:-

http://jptronics.org/Military/bc603/bc603.pdf

There is a section on mods for the BC-603 in the Surplus Radio Conversion Manual Vol 3 which I have digital copies of and which I can e-mail to you. It's 12Mb so probably won't go via this group. Send me a private message if you want it.

73

Roger

[Vecher1]

Anyone know how to change the presets for frequencies>

Skip

[AlanC]

I've never seen one of these radios and this is pure guesswork but having studied the images in the manual that Roger kindly linked above...

Each button actuates a toothed rack which engages with a gear wheel on the tuning shaft and rotates it to a particular position when pressed. Fig 14 shows that for each button, there is a friction washer between the gear wheel and what looks like a disk. I am guessing that the gear wheel is free to rotate on the shaft, but is coupled to it by the friction washer and the disk, which latter is firmly attached to the shaft.

I'm guessing, and it is only a guess, that you can somehow release the friction allowing you to tune to a frequency by turning the tuning thumbwheel, then pressing the desired button, then tightening it again.

I note that there is a hole in the panel above the buttons, which I suspect has to do with this. Looking at fig. 12 on page 11, it looks like behind that hole there is a tube through which you can pass a screwdriver to engage maybe with a clamp screw (?) on the end of the tuning shaft, when the latter is aligned with the hole.

Let me know what you find!

Alan G0NFY

[Vecher1]

ok will do thanks that gets me started in right direction

Skip

[WB6NVH-GEOFF]

I last fooled with one of these in my youth but as I recall, there was a hole you put a screwdriver down, loosened a set screw, and then set the push-buttons after manual tuning.

I hate to rain on the parade here but this has to be one of the most useless pieces of surplus communications gear to put any time into. It was intended to receive wide band FM transmissions between 20-28 MHz, of which there are none today. By wide band I mean 50-60 kHz deviation. The IF is extremely broad, so even if converted to AM it will only be usable on a signal far removed from any others.

The best use for these today is to talk to other BC-603/604 sets in military vehicles, which is not legal in most countries. Decades ago we converted these to monitor highway patrol and police above 30 MHz, but that was a lot of butchery and only worked if there were no adjacent channel stations.

[Vecher1]

I agree with you.. This will be going into a Sherman tank.. I would like to get it working however.. probably will be used as you say maybe tank to tank for demo purpose ..

Thanks

Skip