21-027a AM/FM radio kit HELP!

[Larry4911]

Hi all,
I am fairly new to radio but have been doing other kits for some time now. I decided to get the above radio kit, in order to give me an idea above crystal sets. However I have become stuck after putting it all together.
I cannot find where to inject RF in IF stage. The document is rather vague on this point. I have included the circuit diag and tuning details as supplied.

Also, I am assuming the WOO WOO sound, as mentioned in the document, is dependent on the modulation of my RF generator. In which case I should expect a similar sound to the AF from said generator. Is this assumption correct?

Any ideas/help?

Thanks

Larry

 

[Larry4911]

Has no one any idea?

I have had to edit my post because the pictures didn't post first go.

Anyway I need to know where to feed RF to tune intermediate frequency stage.

Anyone?

 

[audioguru]

Your attachment is not clear enough to see which company makes the very poor quality radio kit.

I don;t see the alignment instructions. Woo-Woo????????? Woo-who?

 

[Larry4911]

Is that any better?

Made by CIC. Chinese tat I know.

 

[Mikebits]

Still does not work.

 

[Larry4911]

What do you mean. Mikebits "Still does not work." Have these never worked?


Larry

 

[Mikebits]

What do you mean. Mikebits "Still does not work." Have these never worked?

Larry

I am talking about your attachment, have you clicked on it?

 

[Larry4911]

Yes, attachment works fine for me.

Larry

 

[Larry4911]

I've moved it on my pc also so it cannot be showing me my picture.

 

[gerty]

Doesn't work from here either..

 

[RadioRon]

Inject a modulated carrier at IF frequency into the junction of C6 and C8 in order to tune the IF stage (to tune "FM/IF ORANGE" transformer, if it is a variable, and the two variable capacitors beside C12). You inject at the input side of the amplifier made up of Q2 so that your RF generator doesn't load and detune the IF circuit you are tuning. Injecting at the input isolates the generator from the tunable elements. It is important to put a DC blocking capacitor in series with your generator output lead to make sure that you don't create a DC path from your circuit back to the generator. Such a DC path would upset the circuit you are injecting into. We like to choose a DC blocking capacitor that offers a relatively high impedance at the carrier frequency so as to further help isolate the generator from the circuit. In your case, perhaps 100 pf or less would be ok.

I can't read the documents, but your assumption is probably correct, that the Woo-Woo is their way of describing modulation on the injected carrier.

If you are going to tune the variable capacitors beside C7 you should probably inject at the antenna input.

 

[Larry4911]

Ok, I'll try it again.

I'm adding it to this post.



Larry

 

[Larry4911]

Well, I can see them?
What's going wrong?

Larry

 

[Larry4911]

Thanks RadioRon. That's exactly what I needed I think.

I'll just b----er off and try it now.

Thanks.

 

[audioguru]

Horray! Your attatchment works!
It shows the schematic of a very cheap AM-FM radio from 1968 (40 years ago).
It has horrible sensitivity and selectivity.
It has horrible distortion from its very poor lousy amplifier.

But it is a lot better than a crystal radio.

 

[Larry4911]

Yes audioguru, but I've got to start somewhere.

Larry

 

[Larry4911]

What about AM tuning?

 

[audioguru]

I can't see your fuzzy schematic and you don't say who makes the cheap kit.
A simple AM radio circuit is extremely simple. If it is a simple super-heterodyne circuit then its oscillator is tuned and its RF amp is untuned and overloads easily.

Look in Google for Super-heterodyne Radio Circuit

 

[Larry4911]

I did say. It's a Chinese company obviously. Called CIC. Now either changed their name or a subsidiary of Allproducts.

This is their advert page the one I've got is the first in the lineup.

https://www.allproducts.com/manufacture11/mes/01-21027a.html

This is probably the same kit they would have sent out to their outworkers in china in the 80's and 90's. I'm sure I saw radios like this on sale in some of the junk (cheap) touristy shops in London in the 80's.

Thanks for your interest and help.

Larry

 

[audioguru]

I have a cheap Sony Walkman radio made in the '80s. It is much, much better than the extremely cheeeeeeeep Chinese one.
The sensitivity of the cheeeeeeeep Chinese radio is horrible, like a crystal radio. I bet its sound is extremely distorted.