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Old 5th Apr 2020, 8:57 am   #1
Nipkowdisc
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Default Fidelity FTV-12 circuit.

I recently came by a Fidelity FTV-12 which is a nice sturdy Monochrome Portable from the early 1980's (I think).

Now this does have a picture and sound (with Freeview Box and Modulator) but the Raster is only about half its proper width and a bit on the dim side. I reckon that this one is worth a repair effort (I hope it's not the L.O.P.T.).

Could anyone supply me with a copy of the Schematic please? I would be most grateful.

Mike.
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Old 6th Apr 2020, 8:44 am   #2
Nipkowdisc
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Default Revised Fidelity Repair Help Request.

Hello fellow enthusiasts

I recently came by a Fidelity FTV-12 Monochrome Portable and I thought I might like to have a go at mending it.
It has low width and a few other little problems.
I wonder if it would be possible to have a look at just the Line Output Stage and Audio Output Stage parts of the Schematic rather than the whole thing in order to comply with the Forum rules.

Mike.
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Old 6th Apr 2020, 9:25 am   #3
Station X
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Default Re: Fidelity FTV-12 circuit.

There is no forum rule preventing the posting of TV service information.
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Old 6th Apr 2020, 7:00 pm   #4
hamid_1
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Default Re: Fidelity FTV-12 circuit.

The Fidelity FTV-12 service data was published in the 1981-82 volume of Radio And Television Servicing.

Unfortunately I don't have this book myself, but I'm sure someone on here will have it and could scan or photocopy it for you.
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Old 6th Apr 2020, 7:25 pm   #5
Heatercathodeshort
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Default Re: Fidelity FTV-12 circuit.

You may discover the fault is in the power supply rather than the line output stage. Just a thought. John.

PS I have scanned and printed the pages you require. If you need them let me have your address via PM and I will post FOC. John.

Last edited by Heatercathodeshort; 6th Apr 2020 at 7:36 pm. Reason: data added.
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Old 6th Apr 2020, 8:15 pm   #6
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Default Re: Fidelity FTV-12 circuit.

Please find attached a PDF copy of the service information for this receiver from the 1981-82 volume of Radio and Television Servicing.
Regards Stan.

Sorry John I did not know you had already done it.
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File Type: pdf Fidelity FTV12 - TVR120 (135%).pdf (177.0 KB, 36 views)
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Old 7th Apr 2020, 9:57 am   #7
Nipkowdisc
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Default Re: Fidelity FTV-12 circuit.

My hearty thanks to hamid_1,Heatercathodeshort and Electrical for their kind provision of advice and information.
I went with Electrical's P.D.F. File as it saves a Stamp.

Looking at the Set then-I started with the Power Supply as Heatercathodeshort suggested and I have 10.8V at the Collector of TR300 so the Regulator would seem to be working.

Mike.
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Old 8th Apr 2020, 8:48 am   #8
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Default Finishing off.

Hello again fellow enthusiasts.

Before leaving the Power supply I would like to say that I think it was quite ingenious how they re-deployed one of the Bridge Rectifier Diodes as a Reverse Polarity Protection Diode during Car Battery operation.

The actual fault was an unsuitable Transistor had been fitted in the TR302 position (it was just a Transistor) and the correct BU807 is a Darlington device with the Efficiency Diode in there as well.

Mike.
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