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-   -   7 Transistor AM Radio Kit (http://www.videokarma.org/showthread.php?t=263989)

captainmoody 04-07-2015 02:34 PM

7 Transistor AM Radio Kit
 
Anyone try building one of those $8 China AM radio kits?

I ended up purchasing one off fleabay, it was eight dollars including shipping from China!

The instructions were in Chinese, I had to figure out the symbols for the color coded IF transformers.. But that was easy enough, as they had them listed for the resistor color code.

Once assembled, it worked great and was a lot of fun to build.. The last one I built was in 1974.. It was an Archer Kit from Radio Shack, and it cost $10 then!

Basically, this is the same thing as the 70's Japanese kit. Only, it runs off 3v instead of 9.

maxhifi 04-07-2015 02:49 PM

eBay link?

captainmoody 04-07-2015 05:19 PM

Will do!

http://www.ebay.com/itm/The-radio-su...item1c42d64397

captainmoody 04-07-2015 05:20 PM

And another:


http://www.ebay.com/itm/DIY-Kits-Sup...item19f754bf02

maxhifi 04-07-2015 05:30 PM

Thanks man, I ordered one... looks like a fun little project.

Username1 04-07-2015 05:48 PM

Neato !

Here is an AM/FM one, but it uses IC chips....

http://www.ebay.com/itm/New-AM-FM-AM...p/310930976499

.

Electronic M 04-07-2015 06:50 PM

Back in 08' (I was still in high-school then) my college had me make a kit radio as part of a summer 'enrollment enticement' course. It was an AM-FM transistor affair with no case.

Gregb 04-07-2015 07:06 PM

When I took electronics in 1970 they had us build a small AA5 tube radio from a kit. It was point to point wired and we had to completely assembly it with no solder and to get a passing grade it had to work. The idea was to teach good mechanical connections.
After that was done we soldered them up and the instruction then inspected our soldering job.

Gregb

Jon A. 04-07-2015 07:52 PM

Quote:

Originally Posted by captainmoody (Post 3130805)
Once assembled, it worked great and was a lot of fun to build.. The last one I built was in 1974.. It was an Archer Kit from Radio Shack, and it cost $10 then!

Basically, this is the same thing as the 70's Japanese kit. Only, it runs off 3v instead of 9.

The Radio Shack kits were still around in the early 90s when I was a kid. They may have been different though; plastic sides, the rest of it cardboard and springs for solderless connections. I built two AM/short wave units; both quit in short order. I'd like to know what I did wrong, if anything. Then of course there was the crystal radio that didn't come with enough wire to make a proper tuning coil. It limped along anyway, and was totally awesome to me back then.

captainmoody 04-07-2015 08:03 PM

I built the AM-FM one with the surface mount chip.. Not a great performer, but fun to build anyway.

maxhifi 04-07-2015 08:40 PM

Yeah I was tempted by FM but thought a superheterodyne would be more fun. This will be a good radio to throw into my travel bag, I always like checking out what's going on, on foreign airwaves.

Electronic M 04-07-2015 08:52 PM

Quote:

Originally Posted by maxhifi (Post 3130860)
Yeah I was tempted by FM but thought a superheterodyne would be more fun. This will be a good radio to throw into my travel bag, I always like checking out what's going on, on foreign airwaves.

Most all FM sets old enough to be knob tuned ARE superhetrodyne type receivers only with a different detector circuit.

If you want a good radio for air travel, and foreign lands look for a good AM-FM-LW-SW portable...Something Like a Sony (some will also tune the Japanese FM band), Grunding, Sangune (spelling), etc. The better SW portables tend to be real good on AM, and some countries have extra bands, or different frequencies for their bands so the more versatile the radio the more you can hear.

maxhifi 04-07-2015 10:19 PM

Quote:

Originally Posted by Electronic M (Post 3130861)
Most all FM sets old enough to be knob tuned ARE superhetrodyne type receivers only with a different detector circuit.

The AM/FM kit above is based on this IC http://kearman.com/images/YD9088.pdf

I suppose if you look at the data sheet, it does work by the same principal as a conventional superhetrodyne, i.e. Rf --> IF --> Detector --> Audio, but it's a super crappy radio on a chip integrated circuit with poor online reviews performance wise, minimal external components, and very little user adjustment/optimization

I picked the AM set because the conventional discrete superhet design looks a little more likely to perform well than the crappy all in one IC solution. Plus building it take longer and be a little more fun.


Quote:

Originally Posted by Electronic M (Post 3130861)
If you want a good radio for air travel, and foreign lands look for a good AM-FM-LW-SW portable...Something Like a Sony (some will also tune the Japanese FM band), Grunding, Sangune (spelling), etc. The better SW portables tend to be real good on AM, and some countries have extra bands, or different frequencies for their bands so the more versatile the radio the more you can hear.

Agreed, I have a digital tuned sony ICF-XXXX (I don't remember the model off hand), which is just fantastic for said purpose, and even sounds great with stereo FM and my Grado SR-60 headphones. But sometimes when I travel I like to avoid taking anything I have any sort of attachment to, and for some reason I am always a little more curious about what's happening on medium wave, than FM.

dieseljeep 04-08-2015 12:00 PM

Quote:

Originally Posted by Gregb (Post 3130845)
When I took electronics in 1970 they had us build a small AA5 tube radio from a kit. It was point to point wired and we had to completely assembly it with no solder and to get a passing grade it had to work. The idea was to teach good mechanical connections.
After that was done we soldered them up and the instruction then inspected our soldering job.

Gregb

Was that a Kelvin kit?
It had a cabinet that was identical to a early 50's Tele-Tone 4 tube radio.
It was a common 5 tube superhet with an isolated B-, as it didn't come with a back.
This weekend, I bought two transistor radio kits. One is a Kelvin AC operated, seven transistor. The chassis looks similar to the tube job, but it's stamped for transistor sockets and small IF transformers. According to the instructions, it's built in several stages and tested before going on. The transformer power supply, first.
The second one is an Elenco, PC board job. Battery operated. :thmbsp:

Gregb 04-08-2015 03:50 PM

I really don't remember a brand, the case was a brown plastic.

Gregb


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