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Where To Get Sets and Parts For discussions about swapmeets, rallies, NVCF and BVWS, car boot sales, antique and charity shops, dealers, newspaper adverts, the local tip and just about any other source of equipment (other than eBay). |
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27th Nov 2017, 1:03 pm | #1 |
Nonode
Join Date: Mar 2010
Location: Dukinfield, Cheshire, UK.
Posts: 2,038
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Another Tesco radio.
I couldn't resist this as it was beautifully marked and up-wind. Just £8.
https://www.tesco.com/direct/tesco-r...?source=others The one in the link is FM only. Note it says 'no longer available'. NOT surprised! Mine is AM and FM but looks exactly the same and has the same model no. Of course we shouldn't expect much at this price and not much is exactly what we get. Both bands are dreadful. On AM, the radio is very insensitive and prefers to pick up its own processor noise. Even on strong signals the audio sounds distant. Tuning is in 9KHz steps and there is a lengthy muting period at every click so you can't tune around like you would on an analogue radio. The ferrite antenna is tiny and appears to be untuned. There's a local oscillator which seems to run about 500KHz high. IF selectivity is poor - I can't see any hardware IF filters so I assume it is done digitally. On FM the story is similar. Poor gain, noises off and generally irritatingly bad. Again no filtering hardware and I couldn't find a LO signal. The chip that does the radio duties is a C9631: http://aitendo3.sakura.ne.jp/aitendo...EN_aitendo.pdf I was thinking of taking it back, but it's chucking it down outside so I'll keep it as a plaything. I may see what it says to my big tuned ferrite sleeve antenna. That'll fix it's clock... Avoid unless you have eight quid burning a hole in your pocket and you fancy something to fiddle with.
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Andy G1HBE. |
27th Nov 2017, 1:12 pm | #2 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,966
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Re: Another Tesco radio.
It's odd how variable these cheap chip based radios are. They all use similar technology and you'd expect the performance to be much of a muchness, but some are much better than others. I suppose some are just bodged together from datasheet examples with an absolute minimum of components.
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27th Nov 2017, 2:52 pm | #3 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,554
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Re: Another Tesco radio.
The RAD-108 is much better apart from the antenna having a tendency to fall to bits.
It also has short wave. |
27th Nov 2017, 2:55 pm | #4 |
Nonode
Join Date: Mar 2010
Location: Dukinfield, Cheshire, UK.
Posts: 2,038
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Re: Another Tesco radio.
Yes, I've got a RAD108 and it's far, far superior to this heap of junk. My 108 is an early one with a standard polyvaricon tuning cap and analogue circuitry, but as there is a lengthy thread on this subject I'll shut up. Oh, the top section of the aerial went missing long ago!
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Andy G1HBE. |
27th Nov 2017, 4:55 pm | #5 |
Guest
Posts: n/a
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Re: Another Tesco radio.
Saved me 8 quid, thank you (always a sucker for a silly electronic thing from Tesco).
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28th Nov 2017, 8:15 am | #6 |
Nonode
Join Date: Jul 2005
Location: Hull, East Yorkshire, UK.
Posts: 2,087
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Re: Another Tesco radio.
I tried the first link....
Favourite music in impressive quality It said. "We no longer sell this product" I wonder why? |
30th Nov 2017, 2:41 pm | #7 | |
Pentode
Join Date: Nov 2007
Location: Cork, Ireland
Posts: 136
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Re: Another Tesco radio.
Quote:
So for example tuned to a station on 100.0 MHz, the LO is likely on approx either 100.125 or 99.875 MHz Very little leaks out, but a narrowband receiver, such as a scanner in NFM mode, will likely receive the LO carrier holding it close to the radio (I found on a similar radio - the Tesco RAD108, the 4th harmonic of the LO could be detectable over a significantly greater distance). Last edited by colourking; 30th Nov 2017 at 2:55 pm. |
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