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Old 28th Sep 2017, 8:43 am   #21
Tyso_Bl
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Default Re: Multiband shortwave radio from Tesco.

Is it `hackable` that's the real issue.
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Old 28th Sep 2017, 9:31 am   #22
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Default Re: Multiband shortwave radio from Tesco.

It looks like my little Philips multiband radio which works very well for its size. I think it uses conventional analogue circuitry.
My little Tecsun PL380 uses DSP circuitry plus a digital display and the batteries last ages. I would think this would be the same for this Tesco radio especially if you fitted some decent quality batteries.
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Old 28th Sep 2017, 9:32 am   #23
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Default Re: Multiband shortwave radio from Tesco.

Quote:
Is it `hackable` that's the real issue.
Don't think it is, when I purchased it I thought it would be an analogue receiver and I could add a BFO.

Dave

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Old 28th Sep 2017, 9:51 am   #24
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Default Re: Multiband shortwave radio from Tescos

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Originally Posted by Nickthedentist View Post
Interesting that the big chains are still selling non-DAB radios in spite of the power that be telling us that they're all but obsolete.
The DAB radios the big chains are selling are obsolete anyway as many do not have DAB+.
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Old 28th Sep 2017, 11:04 am   #25
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Default Re: Multiband shortwave radio from Tesco.

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Don't think it is, when I purchased it I thought it would be an analogue receiver and I could add a BFO.
From what I've seen of cheap CN gear, it seems that they intentionally leave loopholes open, perhaps to create an additional market when news leaks out.

I'm rather intrigued by the resistor controlled bandswitch / tuning, the previous post about a heavy AFC system is prolly a clue as to how its been implemented.
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Old 28th Sep 2017, 5:29 pm   #26
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Default Re: Multiband shortwave radio from Tesco.

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Originally Posted by Herald1360 View Post
Works OK though tuning "feel" is 'orrible and nothing like a normal set- more like something with heavy duty AFC you can't turn off even on AM.
I picked up an AM/FM battery-mains portable with similar design at a Charity shop.
Someone must've tried it and hated it, because it is so hard to tune, as it has the tuner knob on the tuning pot, no reduction, so the user almost has to be a safe-cracker to find their favorite station.
The set's in like-new condition!
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Old 28th Sep 2017, 5:56 pm   #27
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Default Re: Multiband shortwave radio from Tesco.

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Works OK though tuning "feel" is 'orrible and nothing like a normal set- more like something with heavy duty AFC you can't turn off even on AM.
This appears to be a feature of DSP radios with an analogue dial, the frequency selection is carried out in discrete steps.

Quote:
I picked up an AM/FM battery-mains portable with similar design at a Charity shop.
I just picked up a battery only radio at a charity with a similar tuning problem, the make was Radiola.

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Old 28th Sep 2017, 6:26 pm   #28
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Default Re: Multiband shortwave radio from Tesco.

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Originally Posted by usradcoll1 View Post
Quote:
Originally Posted by Herald1360 View Post
Works OK though tuning "feel" is 'orrible and nothing like a normal set- more like something with heavy duty AFC you can't turn off even on AM.
I picked up an AM/FM battery-mains portable with similar design at a Charity shop. Someone must've tried it and hated it, because it is so hard to tune, as it has the tuner knob on the tuning pot, no reduction,
Yes, it appears that this set is not a rival for the one that Superdrug sold some time ago. Do the instructions advise, "After 2 weeks, put it in a drawer and forget about it and after 2 years, donate it to the charity shop"?

B
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Old 28th Sep 2017, 6:45 pm   #29
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Default Re: Multiband shortwave radio from Tesco.

Hi
Just bought one - even for 8 they are theft protected so predictably I set the alarms off and got stopped by security!
Anyway it's not bad and is very like my late lamented Philips in style. Inside's a different matter - big chip and little chip are the order of the day. The only clue to this non-analogue circuitry is the characteristic knife-edge tuning. My tuning scale was crooked, but a moment with a hot iron sorted that out.
Current consumption is typically 70mA - flat out Radio 2 managed to draw 110mA, and SW was broadly similar, so I think the one-hour time is a mistake - I'd suggest ten at normal volume.
Of course only a fool would take the aerial retaining screw out resulting in having to search for the contact washer that would fall out on the floor. Not me, you understand...
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Old 28th Sep 2017, 7:10 pm   #30
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Default Re: Multiband shortwave radio from Tesco.

Quote:
Yes, it appears that this set is not a rival for the one that Superdrug sold some time ago. Do the instructions advise, "After 2 weeks, put it in a drawer and forget about it and after 2 years, donate it to the charity shop"?
I actually found the performance ( sensitivity and selectivity ) far better than the superdrug radio but a lot less hackable.

Does anyone know what the chip is?

Dave

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Old 28th Sep 2017, 7:56 pm   #31
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Default Re: Multiband shortwave radio from Tesco.

Quote:
Originally Posted by Parcgwyn
I just picked up a battery only radio at a charity with a similar tuning problem, the make was Radiola.
Radiola were basically Philips France, though the brand may have been sold on in recent times.
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Old 28th Sep 2017, 8:25 pm   #32
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Default Re: Multiband shortwave radio from Tesco.

I'm tempted to buy one now!

It would be a cert if I had heard about them a few months ago, when I wanted a discounted waterproof DAB from Currys (only available in pink!), but ended up with an Alba DAB from Argos, as it was also going cheap & a smaller version of an Alba I already have.
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Old 28th Sep 2017, 9:57 pm   #33
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Default Re: Multiband shortwave radio from Tesco.

Well I wasn't going to buy one, really I wasn't..

First impressions, comes in a cardboard box in bubble wrap, with usual safety info and guarantee. You'll need the receipt if you break it, so keep that too.

In go two of ALDIs finest AA cells, plug in Sennheisers.

Power and band are self indicating switches, no LEDs exept for the 'tune' one which lights up when receiving a reasonable signal.

Tuning is by rotary knob on the side, it gives the feeling of squelched channel tuning, so no such thing as fine tuning. Picks up R4 on LW, not much on MW, but mostly due to location here, FM good selection of stations here, all in mono.

Tuning through the SW bands, B'cast coverage only, I am rather disappointed that it does pick up all the usual AM broadcasts without the weewoo heterodynes that you normally get with world band cheapos. It does resolve the 7MHz CW as a mass of chirping and beeping. It is surprisingly easy to tune once you get the hang of it, but totally unlike a normal analog radio.

I was rather hoping to break it and get a refund, but I'll take it on site with me tmoz, see how it performs daytime out of doors, tests here done indoors, on the dinning room table at ground level on the built in aerial with two laptops running operating on the same table. At the moment I can't say it's rubbish, a longer test will tell. Perhaps future vintage.
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Old 28th Sep 2017, 10:13 pm   #34
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Default Re: Multiband shortwave radio from Tesco.

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Originally Posted by Andrew2 View Post
MW is OK but the IF filter has poor stopband and our local GOLD is audible for quite some distance on each side!
Is it, I wonder, correctly tuning to the European 9KHz allocations or the US 10KHz ones? If it's not tuning incrementally correctly, that won't help.

I'm still off to Tescos to look for one!

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Old 28th Sep 2017, 10:31 pm   #35
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Default Re: Multiband shortwave radio from Tesco.

The chip appears to either have had the number partially removed or at least covered with some sort of varnish stuff making the markings illegible. It's a DIL SMD device with perhaps 32 pins (only a guess). I'll be taking it to Scotland tomorrow where there's not much of anything intrusive and see how it performs.
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Old 28th Sep 2017, 11:33 pm   #36
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Default Re: Multiband shortwave radio from Tesco.

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Originally Posted by ParcGwyn View Post
Definitely not analogue circuitry, I pulled the back off mine and had a look the day I bought it. Can't remember the chip number, It may have had the number removed.
That's interesting, Glyn. In that case I'm amazed the batteries last so long - about six or eight times as long as the similar batteries in my Sony DAB/FM radio. They last only a week under the same listening conditions, even on FM.
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Old 29th Sep 2017, 2:12 am   #37
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Default Re: Multiband shortwave radio from Tesco.

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Originally Posted by Bazz4CQJ View Post
Quote:
Originally Posted by usradcoll1 View Post
I picked up an AM/FM battery-mains portable with similar design at a Charity shop. Someone must've tried it and hated it, because it is so hard to tune, as it has the tuner knob on the tuning pot, no reduction,
Yes, it appears that this set is not a rival for the one that Superdrug sold some time ago. Do the instructions advise, "After 2 weeks, put it in a drawer and forget about it and after 2 years, donate it to the charity shop"?
That is an excellent observation! Thanks! Dave
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Old 29th Sep 2017, 9:36 am   #38
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Default Re: Multiband shortwave radio from Tesco.

I haven't confirmed this but ISTR that the radio uses the AKC6959 chip - a DSP with resistor range selection and resistive volume and tuning.

The data sheet isn't entirely 'English' but is easily understood:

http://www.datasheetspdf.com/PDF/AKC6959/844678/7
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Old 29th Sep 2017, 10:30 am   #39
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Default Re: Multiband shortwave radio from Tesco.

Great thanks for the link, it looks likely that the chip is AKC6959.

Dave

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Old 29th Sep 2017, 5:13 pm   #40
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Default Re: Multiband shortwave radio from Tesco.

Some pictures of the innards of the Tesco Rad108 multiband pocket radio are to be seen attached to this post in another discussion elsewhere:
no markings visible on the chip

http://www.boards.ie/vbulletin/showp...8&postcount=17


MW sensitivity on the RAD-108 is indeed rather poor despite a longer ferrite rod than some similar budget receivers. Maybe the ferrite rod has dubious composition and maybe substituting another similar sized ferrite rod from a junked old radio might improve matters?

That said with a strong LW/MW signal the audio is crisp, unlike the 'muffled' AM audio from many other recent radios (both DSP and non-DSP) which makes listening unpleasent due to their rolloff above just 2.5 or 3kHz or so.

very acceptable performance on FM for what it is, with good close-in selectivity.
Some images of the whistling+buzzy sounds on portions of the FM band though when used near mobile phone base stations!

On mine - the top section of the telescopic rod came detached after a while (must try and replace it).

Last edited by colourking; 29th Sep 2017 at 5:32 pm.
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