Today's Message Index:
----------------------
1. 05:10 AM - Re: OT: PCB coating removal (rampil)
2. 08:29 AM - Re: Re: OT: PCB coating removal (rayj)
3. 05:30 PM - Re: Re: OT: PCB coating removal (Robert L. Nuckolls, III)
Message 1
INDEX | Back to Main INDEX |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: OT: PCB coating removal |
I don't recall a crystal in my old 1013A, but be that as it may, it seems odd
that someone would use an xtal to generate audio tones unless they needed
extraordinary frequency precision (an a lot of divider steps).
You might try a bit of MEK on a corner of the board. it should not hurt the components,
but might remove the PCB and component printing. The old
potting compounds were pretty resistant to attack.
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=457398#457398
Message 2
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: OT: PCB coating removal |
Thanks Ira,
I'll give mek a try. The board is from an old telephone lineman's test
hand set so it's generating 12 tones for dialing.
Raymond Julian
Kettle River, MN
The things we admire in men, kindness and generosity, openness, honesty,
understanding and feeling are the concomitants of failure in our system.
And those traits we detest, sharpness, greed, acquisitiveness, meanness,
egotism and self-interest are the traits of success. And while men
admire the quality of the first they love the produce of the second.
-John Steinbeck, novelist, Nobel laureate (1902-1968)
On 06/24/2016 07:08 AM, rampil wrote:
>
> I don't recall a crystal in my old 1013A, but be that as it may, it seems odd
> that someone would use an xtal to generate audio tones unless they needed
> extraordinary frequency precision (an a lot of divider steps).
>
> You might try a bit of MEK on a corner of the board. it should not hurt the components,
but might remove the PCB and component printing. The old
> potting compounds were pretty resistant to attack.
>
> --------
> Ira N224XS
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=457398#457398
>
>
Message 3
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: OT: PCB coating removal |
At 10:27 AM 6/24/2016, you wrote:
>
>Thanks Ira,
>
>I'll give mek a try. The board is from an old telephone lineman's
>test hand set so it's generating 12 tones for dialing.
Brings back memories . . . the DTMF tone encoders
of bygone times were indeed crystal controlled.
Here is an exemplar component.
http://tinyurl.com/hzxdjgw
Very popular devices in the ham radio repeater
communities 40 or so years ago.
Bob . . .
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|