Interior of Monika radio from Eltra Audiox, model 410, FM/LW
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I've already shown some older radio receivers, so this time it's time for something more contemporary. Here's a simple budget allotment from Eltra, a portable radio receiver with a long wave and UKF range. Powered by 230V or three LR14 batteries, plus offering a 3.5mm jack headphone socket. I got the equipment from a friend who heard that I like Polish radio receivers, which is not what I had in mind, but let's have a look.... The product is listed on Eltra's website as archived:
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Unlike completely 'no-name' Chinese products, here you can even download the manual and declaration of conformity:
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Manual dated 2015.
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There is a tuning barrel on the housing:
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Now let's take a look inside:
The radio is based on the CD2003:
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A very popular FM/AM receiver chip, available in DIP16/SOP16 housings, operating at 1.8V-7V.
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Also inside here is a single-channel audio amplifier, a TDA2822M:
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A mains transformer is used for the power supply, there is no switching power supply. It is interesting to note that the transformer used is with a centre tap on the secondary winding, there is no four diode rectifier bridge, there is but a two-terminal rectifier:
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Quite poorly these solders look.
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And that's pretty much it... This is not the first time I show the simplest receiver, already before there was also a "typical Chinese" on CD2003, here:
Simple AM/FM radio - Lowry - CD2003GP and D2822A - SC3610D connectable .
The audio amplifier also matches. Only that there is one less rectifier diode here - the battery supply is wired differently.
All in all, no surprises, I wonder if it is possible to find a 1:1 receiver from another seller, without Polish name and markings....
p.kaczmarek2 wrote 11833 posts with
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Comments
Add a commentWhat use are sponges in coils? Stabilisation of the winding? [Read more]
Is long wave reception possible or is it drowning in interference? I wonder how much such a radio can play on battery power. The lack of a switching power supply may make LW reception easier. [Read more]
. Yes, exactly. When the radio was dropped or bumped, for example, the coils were not jittered. [Read more]
. The sponges are soaked in something paraffin-like - the idea is to dampen the vibration of the coil. The voice coil vibrating on impact will detune the circuit and the vibration will be heard in the... [Read more]
Unfortunately, shoddy receivers have been produced for years in which the tuning knob is attached directly to the rotary capacitor. In addition, you have to buy batteries or have access to mains power. I... [Read more]
This is exactly what I wanted to point out - no gear between the tuning unit and the dial, thus zero tuning precision, just to save a few pennies on hardware and scale. It would be interesting to know... [Read more]
. Of course you can, after all it is a typically Chinese cheap product, mashed up on behalf of many companies. Examples: https://www.mediaexpert.pl/telewizory-i-rtv/drobny-sprzet-rtv/radia/radio-nedis-rdfm1340gy-czarno-szary https://www.sencor.pl/przenosne-radio/srd-210-b The... [Read more]
The radio inside is typical Chinese, I've seen and dismantled more than one such radio. Nothing particularly interesting. I have also seen trafka with double winding in this type of equipment, I wonder... [Read more]
. Rather it holds because you can see that there is an ARCz circuit with an additional capacitive diode in the FM oscillator circuit. Thanks to this, you also don't have to precisely tune into the station... [Read more]
Radio very minimalist because the price is also very low. But no one has paid attention to the very extended manual attached to this radio. Now such instructions are not included. [Read more]
. Error. The TDA 2822M itself is a stereo (two-channel) power amplifier, only with the ability to bridge both channels. This manages to produce more power with the same load and power supply parameters. Apologies... [Read more]
That paraffin must have been spilled by someone after a few deep :D [Read more]
@efi222 in older radios it was common to find such paraffin glutes. [Read more]
I found a very similar one branded Blaupunkt. I am posting a photo gallery. [Read more]
Well actually - similar enclosure but different board different scale .... But similar . Even the size is the same (I think?). Only are they VERY similar? [Read more]
Based on a completely different circuit, the C9616. It appears to be an SDR type chip, the tuning is voltage-based (with a potentiometer), there are no variable capacitances, filters, coils in the circuit.... [Read more]
As an excuse for my last post.... A long time ago I bought a cassette player (something a'la WALKMAN) at the local bazaar. Contrary to my earlier fears, it had a very good mechanism with auto-reverse,... [Read more]