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RF transistors list

dsrvital

New Member
Hello! I need a list of RF transistors for an 80-110 MHz transmitter. At the output, I need a powerful transistor, 20 watts.
 

atferrari

Well-Known Member
What schematic have you in mind?
 

dsrvital

New Member
I did not find any power transmitter circuit for these frequencies. I want to transmit data in short pulses, which will not interfere with music.
 

gophert

Well-Known Member
Most Helpful Member
Transmitting at that frequency will be in the FM Radio frequency range and interfere with any of your neighbors attempts to listen to their radios (if any are still listening to radio). You don't need such a high frequency to avoid music - what on earth are you trying to do with 20 watts of broadcast power?
 

gophert

Well-Known Member
Most Helpful Member
Please give some detail of your end goal so we can guide you how to get there - before all the other members jump on this thread to discuss regulations about broadcasting at certain frequencies at certain power and penalties and laws and previous lame experiences they've heard about in countries that you don't live i.
 

ronsimpson

Well-Known Member
Most Helpful Member
There are some radio frequencies where you can send data long distances with out licenses but under certain conditions. That is why we want to know more.
I have used ZigBee 900mhz radios and 2.4ghz radios. The 2.4 I used for years at 5 miles with good antennas. The 900mhz will do better outdoors. You can not transmit all the time, must leave time in between bursts of data. I looked at " LoRa " radio but did not use it.
There are some other frequencies for data that I have not used. One is only for "medical".
How far do you want to send data?
 

dsrvital

New Member
I live in Ukraine. I want to make a FM radio transmitter for my projects. Range 5 km and more. I think that a microwave is just a waste of money, power and health. FM will go much further than Wi-Fi. 27 MHz I do not want to use, too clogged range. A large antenna is needed for 3 MHz. Only FM remains.
del.
 
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dsrvital

New Member
OK. My actions will be legal. I'm looking for any transistors with a maximum frequency of 500 MHz. For the 433 MHz radio transmitter. No FM. But FM may be compatible. Legal
 

Nigel Goodwin

Super Moderator
Most Helpful Member
OK. My actions will be legal. I'm looking for any transistors with a maximum frequency of 500 MHz. For the 433 MHz radio transmitter. No FM. But FM may be compatible. Legal
Nothing you've written there suggests any way it's legal - and while I've no idea what the regulations are in the Ukraine it seems VERY unlikely it would allow high power unlicensed radio transmissions.

It also seems highly unlikely you would be capable of building such a device, when you can't even find a suitable output transistor (which is likely to be by far the easiest part).
 

dsrvital

New Member
High power transmitters are prohibited in Ukraine. BUT the output power depends on the antenna. In order not to clog the radio with harmonics, a filter is installed at the output, which further reduces the power. The radio equipment, which is imported to Ukraine, is connected in series with the antenna with a capacitor to reduce the power and a UCFR sticker is glued.
 

unclejed613

Well-Known Member
Most Helpful Member
radio rules are governed by international agreements, and Ukraine is in ITU Region 1. there may be slight variations in each country, but generally the rules for the FM broadcast band in Ukraine are going to be very similar to what they are in the UK. under certain weather conditions, signals in that band can be carried hundreds of miles. it's called "tropospheric ducting" and it usually happens along a strong cold or warm front where there is a line of strong storms. so, it's unlikely that the rules allow more than a watt or so (assuming "home broadcasting" is even allowed). another thing is that in certain bands, only specific modulation methods are allowed. you can't use FM in the AM broadcast band, and you can't use digital in the FM band unless the digital system is operated with an FM station and the digital system is approved (like RDS and Digital Radio in the US) look for an ISM band to operate in and check the rules in the Ukraine for using unlicensed devices. i can't imagine that jail in the Ukraine would be a very pleasant vacation spot.
 

gophert

Well-Known Member
Most Helpful Member
dsrvital , You better listen to Nigel Goodwin . He certainly knows how easily transistors can be found in the Ukraine.
 

gophert

Well-Known Member
Most Helpful Member
Or, we can assume the OP knows what he is doing and, like the OP said, 20W circuit doesn't mean 20W of transmitted energy.
 

atferrari

Well-Known Member
Or, we can assume the OP knows what he is doing and, like the OP said, 20W circuit doesn't mean 20W of transmitted energy.
I do not intend to play the expert by any means, here, but if I understood it right, the power of any transmitter, unless specifically defined in a different way, is defined as the power applied to the final output stage. Am I to much off track?


The filters applied, surely would attenuate the emitted power but I am not sure they would take part of the definition.

Sure I would like hear an authorized clarification.
 

gophert

Well-Known Member
Most Helpful Member
I have some New Old Stock Motorola (Macom is still selling them with their own tags on them - about 30-years old).
The best I can find in the 20-30 watt range but nowhere near your 100MHzrange. Only up to 30MHz. I'd have o check if there are any export limitations.

 

dsrvital

New Member
I don't like it when someone tries to ban what's left. Ukraine has already passed many laws that have been asked to be adopted by the EU, which have restricted citizens. I'm not saying that I'm allowed to broadcast in the FM band. Ukraine has a permitted band of 27 MHz. It can use any modulation. Power should be no more than 10 watts. Each transmitter at 27 MHz, outputs harmonics at 56 MHz, 81 MHz, 112 MHz. You can broadcast without a license. Therefore, I can assemble a 27 MHz transmitter without a high pass filter, but it will broadcast at the specified frequencies. I came across things that are allowed in Ukraine, which give a signal on these and other frequencies. For example, a Chinese charger can turn off all FM radios at once. (5 Watts, 20 meters).
I have already assembled such 1 W transmitters. They work no further than 20-100 meters. This transmitter will operate at 400 meters - 2 km
 

dsrvital

New Member
Persuaded. I'm hiring someone to make me a licensed 27 MHz transmitter. But I will buy a transistor.
If not 20 watts then at least 2 watts.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
I have already assembled such 1 W transmitters. They work no further than 20-100 meters.
You've not built it properly then - 1W at 27MHz should easily go a number of miles - presuming you're outside?, obviously if you're inside walls and obstructions will restrict range. In fact, under the right conditions, 1W at 27MHz will easily cross the Atlantic ocean.

As a radio ham, on 145MHz (2M) it's normal to get 60-70 miles range using just one watt on a handheld transmitter - needs to be top of hill to top of hill though, otherwise the curvature of the earth gets in the way.

Your Chinese charger was almost certainly faulty, with high ESR electrolytics causing massive RFI - a VERY, VERY common fault with cheap electrolytics and their short life span.
 

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