walkie-talkie

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cocoloco

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hi there
i am making one circuit for about 3 months lol
http://talkingelectronics.com/projects/200TrCcts/200TrCcts.html#64
now i feel that im on the right way , but i have a doubt about one thing
take a look at this image
View attachment 66081
does it mean that all the elements which are going to the minus ( same about plus ) , could be connected to one dot , and without any sequence ?
i could draw if you need it / cant get what i mean
please , any opinion ? ?
 
If you mean the polarity indicators on the electrolytic capacitors then no, they must be connected as shown.

By the way, that circuit requires a 3PDT momentary switch which may be difficult to find.
 
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Oh, you mean component connections to the power and ground rails. You can place the parts how you like as long as you pay attention to preventing unwanted interstage coupling especially around inductors, transformers and the speaker.
 
huh , i failed again . i will make my speech short
so what do i have now : it works fine when turns on , i can hear a loud white noise perfectly without antenna , but when i switch few times or press call key — it goes to BZZZZZZZZ and PSHHHHHHHWZZZZZ very loud , its real torture for my ears .
and what do i ask now :

i have heard that smd transistors bc847-bc857 have hfe about 100 , when bc547-557 (have seen that on my own eyes) have it 480-540 . so , if i put bc8** instead of bc5** transistors , will a pair of this walkie-talkies have a lower (1/5) distance of working or they will not ?

sorry for broken english
 
First off never transmit without the ant or a dumy load hooked up.
2nd you maybe getting feed back if the two units are to close.
3rd If you do not switch both of the switchs at the same time you can damage the circuits. You realy need the right PTT switchs.
 
thanks for response
1) + 2) if you mean "2 units" are 2 walkie-talkies :im talking about testing 1 single circuit in receiver mode , without antenna . it should have white noise if it work normally
3) completely agree
they both worked fine for a short time only
what could you tell me about gain of smd-transistors? possible range of work will be reduced or not?
 
quite frankly im getting sick and tired every time i look at my unfinished device
everything seems to be in order , except the damn coil
so how to wind an oscillator coil correctly ?
place 2 turns under 4 turns , or 4 turns under 2 turns ? or its not matter , so i just need to place wires back-to-back , above each other , near each other , as much as it possible ?
here is mine madskills
View attachment 66804
 
why cant i edit prevpost ?

3rd If you do not switch both of the switchs at the same time you can damage the circuits. You realy need the right PTT switchs.
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left slide switch on my previous images is toggling capacitors 15p and 5n capasitors only ( only 3 of 6 contacks are used ) , i still think this is acceptable

also what about the topside of the coil ?

View attachment 66805

sorry i cannot into english thats why i draw like a monkey
 
so how to wind an oscillator coil correctly ?
Click to expand...
Thats a good questoin!
Maybe AG can Help.
I do know its a RF tuneable transformer with a tapped primary.
You must make complet turns around the former.
Most transformers I have seen have one coil low on the former and the other higher.
I would try the one turn on the bottom with the other three right above it and put the other coil just higher.
 
Your coil should look something like the attached picture.

It is a bit untidy and ugly and serves no purpose other than to show what a two winding coil should look like.

Looking at the circuit which you are proposing to build, if you want this thing to work somewhere near 27Mhz, 3 turns on the coil is not enough.

Look at the other 27Mhz circuits in that link, thay all use more than 3 turns.

13 turns sounds better to me.

JimB
 
Jim thanks for taking the time to post that pic. Its worth a thousand words.
Could you show him what the tap should look like?
 
4pyros;1080943 Maybe AG can Help.[/QUOTE said:
No.
I have never made an RF circuit at the low frequency of 27MHz and a coil with a ferrite core.
I have never made a crappy "super-regen" radio.
Click to expand...
 
Jim thanks for taking the time to post that pic. Its worth a thousand words.
Could you show him what the tap should look like?
Click to expand...

What a slave driver!

OK,

1 Carefully scrape the enamel on the wire to expose the copper.
(The enamel on modern wire will burn off with the heat of a soldering iron, but scraping to expose bare copper makes life easier).

2 Tin the exposed bit of the coil.*

3 Tin the wire which forms the tap.

4 Solder them together.*

5 Job done. Easy.

* If the coil former is made of a thermoplastic material, take care not to melt the former!

JimB
 
**broken link removed**
unfortunately this trick with a piece of solder is not available when using 0.25 magnet wire and thin coil . since this is hf , may i ask you : can i use another trick , which shown in image below ?
**broken link removed**
KJ6EAD said:
You can place the parts how you like as long as you pay attention to preventing unwanted interstage coupling especially around inductors, transformers and the speaker.
Click to expand...
this is interesting
look **broken link removed** , ive placed a dynamic (3) on the centre of the "ground" , maybe i was wrong ? and transistor 3 gets supply before transistor 2 gets it
suspicious placement
is there any clearly explained rule (-s) or example (-s) , about " which element should not stay on the way ( trace ) , from one element to another " ?
 
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When making a small coil with thin wire, do it as shown in the attached pictures.

JimB
 
btw, when 2 regen radios are near each other, they interfere with each other, even when they're not transmitting. this is one reason regen radios are usually only a curiosity, because they radiate RF even in receive mode (what the FCC calls "unintentional emitters").
 
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