|
Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
|
Thread Tools |
4th Jan 2016, 7:57 pm | #1 |
Hexode
Join Date: Dec 2015
Location: Walsall, West Midlands, UK.
Posts: 327
|
Difference between CH.1 and CH.2
Hi folks,
Apologies for another newbie question... On the trader sheet for my first project I see what is a symbol for the chassis ground but in some cases it says CH.1 and in others it says CH.2 (see attached). can anyone explain the difference? Also on the switch layout the switches are labeled S1, S2 etc but on one switch bank there is a "BE" see attached. I dont know what the difference is here either. thanks |
4th Jan 2016, 8:16 pm | #2 |
Dekatron
Join Date: Jun 2013
Location: East Sussex, UK.
Posts: 3,315
|
Re: Difference between CH.1 and CH.2
Don't think we can tell from only that small bit of info. What set is it? We can then look at the circuit to see what is there.
|
4th Jan 2016, 9:38 pm | #3 |
Nonode
Join Date: Jun 2007
Location: Coulsdon, London, UK.
Posts: 2,152
|
Re: Difference between CH.1 and CH.2
Are you working on a dual channel oscilloscope?
|
5th Jan 2016, 12:25 am | #4 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,526
|
Re: Difference between CH.1 and CH.2
Are there two chassis by any chance?
__________________
....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
5th Jan 2016, 1:11 am | #5 |
Hexode
Join Date: Dec 2015
Location: Walsall, West Midlands, UK.
Posts: 327
|
Re: Difference between CH.1 and CH.2
The set is a Regentone A.155
It looks like it's the chassis but I wonder why .1 and .2? |
5th Jan 2016, 1:14 am | #6 |
Octode
Join Date: Jan 2013
Location: Barnsley, South Yorkshire, UK.
Posts: 1,517
|
Re: Difference between CH.1 and CH.2
Could it be a stereo device and it simply means Ch2 layout is the same as Ch1; the complete circuit being shown for one channel and just the switching being shown for the second?
|
5th Jan 2016, 1:42 am | #7 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
|
Re: Difference between CH.1 and CH.2
From the Trader circuit, Ch1 is the VHF tuner chassis and Ch2 is the main chassis. ERT doesn't distinguish between them. Be only appears on the bandswitch drawing, possibly unused contacts?
|
5th Jan 2016, 1:47 am | #8 |
Dekatron
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,385
|
Re: Difference between CH.1 and CH.2
Radio chassis often have earth-tags stamped out of the chassis in the form of a tongue of metal that various components or wires are wrapped around. Theory says that "earth" is "earth" but in the real world of wiring and sheet metal of significant dimensions, resistance and impedance appear- maybe very low but possibly significant. Sometimes, it's good to separate earthing points for different parts of the circuitry- for example, earthing the power supply capacitors and oscillator/mixer section to the same point on the chassis might under some circumstances introduce an incurable background warble, so they get connected to differing points on the same chassis, hence the "CH.1" and "CH.2" designations. In other cases, such as audio amplifiers, it can be important to have a single point earth to avoid instability. Earthing layout in electronics is frequently a combination of sound theory, long practice and finally a bit of oh, , let's try putting this one here....
Sometimes in mains transformer-less ("AC/DC") sets, it could indicate that they are separated by isolation capacitors and it becomes very important for electrical safety to connect the right component to the right place! |