signal Can someone break down how this receiver works

Posted on Feb 7, 2014

It is on top labled toy car receiver. The toy car transmitter is easy enough to understand, and I suspect that the receiver is essentially working the same way, but backwards and with more filtering. I have no experience in RF except that I saw this circuit before and asked someone how it works. The first stage is tuned at 27, 145 Mhz and will pickup the signal in this frequency. After that, it is all amplification and level

translation or relay driving. Most of the designators are missing. I think people will have hard time explaining. abdullah kahraman Dec 15 `11 at 6:13 @abdullahkahraman I figured out the 1st and 2nd stage (sort of) already. Could you explain the 3rd part in more detail. I don`t understand what you mean by level translation. sj755 Dec 15 `11 at 6:17 I don`t know in detail, too. That`s why I commented on it. However, 680k and 2. 2k and 10k are for biasing the 3rd transistor. 100n is for coupling. 1n is to have negative feedback in high frequencies thus, reducing the gain. I don`t know what those diodes are for but one of them is probably a kickback diode. Maybe one of the diodes is to take negative feedback over lower 40n in only one direction. The upper 40n cap could be for high frequency current limiting. I am just thinking loudly, btw. That`s why this is a comment. abdullah kahraman Dec 15 `11 at 6:25 @abdullahkahraman And great comments like these is why I upvote. You have been greatly helpful. I`d appreciate any further input. I`ll continue waiting for a complete answer though. sj755 Dec 15 `11 at 7:22 DC point is given by resistors, taking capacitors as open circuits and taking inductors as short circuits. On output dc bias is 6. 1V and collector voltage dc point is 5. 5V. Ic = 410uA aprox. Green marked network formed by C2, R3 and C6 is a low-pass filter for negative feedback. It stabilizes the gain loop and stretchs...

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