ZX21: CERAMIC RESONATOR
ZX21: CERAMIC RESONATOR
I am puzzled as to how the ceramic resonator is wired on the ZX81?
It seems to only show two terminals but the device has three terminals?
It seems to only show two terminals but the device has three terminals?
FordP (Simon Ellwood)
Time is an illusion. Lunchtime, doubly so!
Time is an illusion. Lunchtime, doubly so!
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Re: ZX21: CERAMIC RESONATOR
The middle pins goes to ground by the looks of it:
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Re: ZX21: CERAMIC RESONATOR
Thanks.
The bottom is OK to trace but the top is hard due to the silk screen and my dodgy eyes!
FordP (Simon Ellwood)
Time is an illusion. Lunchtime, doubly so!
Time is an illusion. Lunchtime, doubly so!
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Re: ZX21: CERAMIC RESONATOR
From the top from a photo I took of a zeddy I desoldered and rebuilt:
Hopefully I counted the ULA pins numbers correctly.
Pretty sure looking at it the top pin is not connected. It looks like it in the photo but I think that is just a scratch.
Hopefully I counted the ULA pins numbers correctly.
Pretty sure looking at it the top pin is not connected. It looks like it in the photo but I think that is just a scratch.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
- 1024MAK
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- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: ZX21: CERAMIC RESONATOR
The middle (centre) pin is connected to 0V/GND, one of the outer pins connects to C6, the other outer pin is not connected to anything.
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer being good this year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer being good this year.
Re: ZX21: CERAMIC RESONATOR
Thanks for your help. That's what I thought but it still looks wrong to me!
Is there a known part code for the resonator? I think that will be the hardest to source new (after the ULA but we know they do not sinclair ULAs).
Is there a known part code for the resonator? I think that will be the hardest to source new (after the ULA but we know they do not sinclair ULAs).
FordP (Simon Ellwood)
Time is an illusion. Lunchtime, doubly so!
Time is an illusion. Lunchtime, doubly so!
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- Posts: 2202
- Joined: Sat Nov 26, 2016 2:42 am
Re: ZX21: CERAMIC RESONATOR
Good luck with the resonators. When I rebuilt a zeddy from scratch (viewtopic.php?p=27533#p27533) I had endless fun with them.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
- 1024MAK
- Posts: 5189
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: ZX21: CERAMIC RESONATOR
They are actually normally used as part of a filter circuit in, for example, analogue televisions. Hence are rather hard to find these days.
Mark
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer being good this year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer being good this year.
Re: ZX21: CERAMIC RESONATOR
Does this look right?
https://www.reichelt.com/gb/en/ceramic- ... 3.html?r=1
https://www.reichelt.com/gb/en/ceramic- ... 3.html?r=1
FordP (Simon Ellwood)
Time is an illusion. Lunchtime, doubly so!
Time is an illusion. Lunchtime, doubly so!