Before we drop the tuner I have to ask a couple of questions.
Looking at the parts list there are three capacitors (C1,C2,C41) listed as LL-Electro which I assume means low leakage electrolytic. I have no idea how good those original caps would have been but I would guess that with progress in manufacturing and materials over the 37 years since the tuner was made that any decent modern production cap would be up to the required level without having to search out a special quality cap. Yes?
The other question is a bit more general and has to do with how much isolation the rf tuning circuit can be safely assumed to have from the audio and power supply circuits. There are a number of electrolytic capacitors not in the power supply, in different places on the board and not having all the test tools listed as required in the service manual I'd like not to do anything that ends up invoking the need for an alignment. Is the rf circuit variability dependent solely on components within the tuning circuit?
Thanks !!
Looking at the parts list there are three capacitors (C1,C2,C41) listed as LL-Electro which I assume means low leakage electrolytic. I have no idea how good those original caps would have been but I would guess that with progress in manufacturing and materials over the 37 years since the tuner was made that any decent modern production cap would be up to the required level without having to search out a special quality cap. Yes?
The other question is a bit more general and has to do with how much isolation the rf tuning circuit can be safely assumed to have from the audio and power supply circuits. There are a number of electrolytic capacitors not in the power supply, in different places on the board and not having all the test tools listed as required in the service manual I'd like not to do anything that ends up invoking the need for an alignment. Is the rf circuit variability dependent solely on components within the tuning circuit?
Thanks !!
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Use Nichicon UKL series as low leakage replacements. They are usually recommended to be used in the signal paths and other critical places. They can also be used for general purpose ecaps unless you need lower ESR or higher ripple current types for power supply application
The RF front end , LO, Mixer is basically isolated, from the IF sections and there after but the power supply can affect their operation. I only see 3 ecaps in the RF pcb. You can use Nichicon UPW for them.
Items like C21,C31 have no effect on the tuning adjustments. C33 in the AFC is rather benign, acts as a DC filter.
Where are you located in Canada?
You can ask as many questions as you want, I will try to answer them, however I am no expert on this tuner.
On what pcb's? X00-2070-11?
The RF front end , LO, Mixer is basically isolated, from the IF sections and there after but the power supply can affect their operation. I only see 3 ecaps in the RF pcb. You can use Nichicon UPW for them.
Items like C21,C31 have no effect on the tuning adjustments. C33 in the AFC is rather benign, acts as a DC filter.
I guess you are referring to the RF pcb (X01-1310-11) which I commented on above.
Where are you located in Canada?
You can ask as many questions as you want, I will try to answer them, however I am no expert on this tuner.
SDR means something different to each user.
There are tiny TV tuner dongles that directly convert an RF signal to baseband, then digitize it with 8 bit converters. These cover about 50 MHz to 1.something GHz and cost about $20 on Amazon. The rest is all software. The one I have was useless in south Florida where I had an LTE cell tower about 200 feet outside my front door, and 125 KV power lines across the street. It works reasonably well here since there are virtually no RF signals here.
There are the "soft rock" and compatibles, one or two steps up the performance ladder, because they use some RF front end filtering and 16 bit converters.
Then there are full blown multiple conversion receivers with different IF's and IF bandwidths for different purposes, and frequency coverage from DC to daylight. All is reduced to a low frequency IF to suit the mode, digitized and applied to a processor for demodulation.
My first attempt will be somewhere between the second and third definition, eventually leading to the ultimate radio along the lines of the third definition. All will try to make good use of existing software.
It may be a while before I gather all the material and equipment that I need to really get started on this, but I'll post the progress somewhere.
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