|
Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
|
Thread Tools |
12th Mar 2020, 8:05 pm | #1 |
Banned
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
|
Desecrated Roberts 404 module.
Opened up this 404 earlier and took chassis out and this is what I found. Words fail me . They have destroyed the traces in the module that the screen wires of AF117s that have whiskers were connected to.
When I get the module out I will put some pics up of what I found. Regards Poppydog |
12th Mar 2020, 11:39 pm | #2 |
Banned
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
|
Re: Desecrated Roberts 404 module
Got the module out and this is how it looks, I can use some tinned copper wire to remake the screen connection. I have acquired radios that have had minor bodges to get them going but never as brutal as this.
Regards Poppydog |
13th Mar 2020, 9:15 am | #3 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,433
|
Re: Desecrated Roberts 404 module
Has someone drilled two holes through the PCB and screening can to get at the modules PCB? That’s what it appears but surely not.
That would be an entry for bodge of the year.
__________________
Frank |
13th Mar 2020, 9:25 am | #4 |
Banned
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
|
Re: Desecrated Roberts 404 module
There are 2 pre- drilled holes in main board to give access to the transistors in the module to enable you to take voltage readings etc. The af117s were suffering from whiskers so the offender scratched out the traces to the screen leads in an attempt to get it to work..
poppydog |
13th Mar 2020, 12:49 pm | #5 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,433
|
Re: Desecrated Roberts 404 module.
Thanks! I understand now.
__________________
Frank |
13th Mar 2020, 7:02 pm | #6 |
Heptode
Join Date: Apr 2016
Location: Cheltenham, Gloucestershire, UK.
Posts: 875
|
Re: Desecrated Roberts 404 module.
Vandalism [or sheer laziness from somebody who should have known better]! Obviously it's 'fixable' ... but a pain nevertheless.
It's a dirty job - but you're the right guy to do it Steve!!!
__________________
Red to red, black to black. Throw the switch and stand well back! |
13th Mar 2020, 7:12 pm | #7 |
Octode
Join Date: Jul 2004
Location: Evesham, Worcestershire, UK.
Posts: 1,422
|
Re: Desecrated Roberts 404 module.
Appalling laziness but not surprising, in fact that's quite neat to what I've seen in my time, and pointless really as it's not just the shield connection that's the problem with the af-xxx range.
Greg.
__________________
Picture, sound?, DOOR. |
13th Mar 2020, 8:58 pm | #8 |
Hexode
Join Date: Dec 2011
Location: Wigan, Greater Manchester, UK.
Posts: 291
|
Re: Desecrated Roberts 404 module.
The question is are you going to fit AF11X series transistors as replacements? The AF12X series may have 4 leads but are a lot smaller and defeat the originality of the radio. The transistors will be enclosed in the IF can and cannot be seen. I fit BC557 transistors and they work really well. I also do like what a lot of valve radio repairers do (re-stuffing capacitors). I dig out the AF11X transistor and stick the can over the BC557 on any radio that needs a replacement transistor that is visible.
I see from your second photo the RF transistor has been replaced by cutting out the original and soldering in a replacement using the cut leads to solder in the replacement. I think in the 60s and 70s this was quite common for economical repairs to transistor radios. Last edited by Davewantsone; 13th Mar 2020 at 9:16 pm. |
14th Mar 2020, 2:41 pm | #9 |
Banned
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
|
Re: Desecrated Roberts 404 module.
I think its been done by someone who obviously has some knowledge of whats what
I did think about putting in a request for a module but changed my mind and thought I would re-use this one as the radio itself wont win any awards, but will clean up ok. I have already removed the af117s and last night I started to install gt322bs into the module, I thought I might try a AF13X type for the osc as I've never used them as replacements for the AF117s before. The usual trouble with the traces lifting on the main board upon removal of the module needs sorting, I have found the stand alone/single pads are the worst regards poppydog |
14th Mar 2020, 5:55 pm | #10 |
Banned
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
|
Re: Desecrated Roberts 404 module.
I have saved the module board, it's had two GT322b in place of the AF117s, both electrolytics replaced and the screen connections remade with a couple of bits of lead out wire .
I am not going to bother to try and sort out the mess on the screening can that covers the module board, it will be a loss cause. Regards Poppydog |
14th Mar 2020, 6:17 pm | #11 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,433
|
Re: Desecrated Roberts 404 module.
Nice decent repair.
__________________
Frank |
21st Mar 2020, 9:32 pm | #12 |
Banned
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
|
Re: Desecrated Roberts 404 module.
Thanks Frank .
The module has now been replaced. The osc transistor is now a af138S and its all working very well with not a single adjustment having to be made. It's actually a very good sounding radio and is extremely sensitive, just a shame there isn’t any music to listen to now on LW/MW. Regards Poppydog PS. it wasn't me that scratched the leadout positions on the board in front of the osc transistor . |
21st Mar 2020, 9:37 pm | #13 |
Dekatron
Join Date: Aug 2007
Location: W.Butterwick, near Doncaster UK.
Posts: 8,932
|
Re: Desecrated Roberts 404 module.
Great job.
__________________
G8JET BVWS Archivist and Member V.M.A.R.S |
29th Mar 2020, 10:07 am | #14 |
Banned
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
|
Re: Desecrated Roberts 404 module.
|
29th Mar 2020, 9:57 pm | #15 |
Heptode
Join Date: Apr 2016
Location: Cheltenham, Gloucestershire, UK.
Posts: 875
|
Re: Desecrated Roberts 404 module.
That's a very nice neat job Steve - once the traces are lifted [and discarded!] you can never 'make a silk purse out of a sows ear' ...... unless you etch a whole replacement PCB.
I'd be happy with what you've done/achieved.
__________________
Red to red, black to black. Throw the switch and stand well back! |
30th Mar 2020, 9:12 pm | #16 |
Banned
Join Date: Oct 2015
Location: Cornwall, UK.
Posts: 849
|
Re: Desecrated Roberts 404 module.
Thanks for the reply David. I asked in my previous post what other/better way could it be repaired, but for a reliable and permanent repair I think other than replacement, the way I did it is probably the right way.
Regards Poppydog |
30th Mar 2020, 9:24 pm | #17 |
Nonode
Join Date: May 2016
Location: Cornwall, UK.
Posts: 2,335
|
Re: Desecrated Roberts 404 module.
It's funny - I see those scratches and markings as a positive. They're a visible remnant of the history and approaches of the different users the radio's had in its long life. In the British Museum there's a protective screen over the game board scratched by some bored, ancient soldiers on the leg of an Assyrian Lamassu!
I'm not detracting from the repair at all though - it looks solid, well-made and suitable. |