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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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5th Sep 2020, 1:55 pm | #1 |
Pentode
Join Date: Oct 2018
Location: Carrickfergus, County Antrim, Northern Ireland, UK.
Posts: 126
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Ic2e circuit diagram
Hello, I am looking for a decent circuit diagram for an Icom IC2E. Yes an oldie I know but I have one which I suspect has a dud crystal in the PLL. I have just bought a scope and I was hoping to faultfind this rig. It stopped working after it was dropped. There is no rx noise when the squelch is opened and no transmit, hence my suspiscion of the clock crystal being damaged.
Any help appreciated. Dave |
5th Sep 2020, 2:07 pm | #2 |
Heptode
Join Date: Jan 2008
Location: Birchington Kent, UK.
Posts: 596
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Re: Ic2e circuit diagram
Hello Dave
highly readable circuit in the manual here:- http://www.radiomanual.info/schemi/I..._AT_E_serv.pdf
__________________
Regards Pete |
5th Sep 2020, 3:06 pm | #3 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,015
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Re: Ic2e circuit diagram
No RX Sq and No TX is sometimes the PLL not being locked and so both are inhibited.
As you said maybe the drop test has broken a crystal? If it doesn't work on any range simplex/duplex etc then X1 the 5.12MHz on the TC5082 is most likely Last edited by Jon_G4MDC; 5th Sep 2020 at 3:21 pm. |
5th Sep 2020, 3:18 pm | #4 |
Pentode
Join Date: Oct 2018
Location: Carrickfergus, County Antrim, Northern Ireland, UK.
Posts: 126
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Re: Ic2e circuit diagram
Thanks Pete that is very useful.I should be able to work through the set once I get my scope.
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8th Sep 2020, 9:53 am | #5 |
Dekatron
Join Date: Aug 2011
Location: Newcastle, Tyne and Wear, UK.
Posts: 11,553
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Re: Ic2e circuit diagram
A crystal oscillator is basically a very low power radio transmitter, so if you know what the suspect crystal frequency should be, try 'listening' for it on a comms receiver or scanner.
With the receiver on AM mode you should see a steady signal on the meter when the crystal is running. If the receiver has SSB, go to USB mode and tune slightly on the low side (-500Hz), of the expected frequency and you should get a steady tone or whistle when the crystal is running. If you connect any sort of test equipment directly to an oscillator it can sometimes detune or even stop the oscillator, using a receiver to 'sniff' for the oscillator avoids that potential problem. |
8th Sep 2020, 10:40 pm | #6 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,015
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Re: Ic2e circuit diagram
I think the novel thing with the IC2E is the 5kHz offset switch and how it is applied to 4 different crystals by a diode switch arrangement on several different pulling coils.
Icom in that era knew their stuff about crystal oscillators having made the IC202 series of 2m SSB rigs which were all VXO based using 200kHz tuning ranges. I found it surprising that an RX crystal from the IC215 (their bog standard FM rig) worked pretty much just as well in an IC202 VXO. 15MHz fundamental x9 +10.7MHz if I recall. |