Author Topic: Need info about this FM transmitter (1 of 2)  (Read 1565 times)

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Offline MerlysysTopic starter

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Need info about this FM transmitter (1 of 2)
« on: May 03, 2016, 06:24:16 pm »
I want an FM transmitter to do some experiments with (using load)
http://www.ebay.ca/itm/222099498416

Specs are given as
  - Output power: 3 DBM - 15 DBM
  - Working frequency: 85 MHZ--115 MHZ

Is this really an FM transmitter? If so what would the max power output be? Is it possible to convert dbm to watts?


 

Offline xrunner

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Re: Need info about this FM transmitter (1 of 2)
« Reply #1 on: May 03, 2016, 06:34:37 pm »
Is this really an FM transmitter?

Well, that's what they claim. Buy one and see.  :-//

Quote
If so what would the max power output be? Is it possible to convert dbm to watts?

dBm is power relative to 1.0 mW. 0.0 dBm is 1.0 mW of power, so (+) 3 dBm would be twice that or 2.0 mW. (+) 15.0 dBm is 31.6 mW output power.
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Offline Ammar

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Re: Need info about this FM transmitter (1 of 2)
« Reply #2 on: May 19, 2016, 12:40:33 am »
It very much could be. I assume those SOT-23 packages are discrete transistors. I don't know why they have bothered when there are many integrated solutions. Looks like a cheapy. Expect the frequency to drift if you do get it.
 

Offline mos6502

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Re: Need info about this FM transmitter (1 of 2)
« Reply #3 on: May 19, 2016, 08:01:06 am »
It's just your standard 3 transistor FM bug. Dozens of circuits out there. Transistors used:

J6 - probably MMS9014
J8 - MMS9018
for(;;);
 


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