Old veronica transmitter 12w fault

[yellowbeard]

The 2N2219A is good for about 250 - 300mW at 100MHz and has been for 50 years!

[Krakatoa]

Yes, the 2N2219 works at VHF but it has worse and unfavourable caracteristics than a proper RF transistor. It works, but needs tweaking because of the higher internal capacitances.
In fact, I have seen schematics from the late 60's when there was almost nothing better available, where it was used in common-base configuration as output device for a portable transceiver (common-base connection cancels the inter-electrode capacitance of the transistor and extends its useful amplification frequency, while giving better stability).

[radium98]

I saw it used in smart kit 1028 . Thanks for the many replies useful , but i still not understand why not producing anything , it is legit , not fake , also if i swap with 3866 it deliver like a half of a watt .Strange

[Albert H]

The match conditions for the '3866 and the '2219 are quite different. You have to bear in mind that there are many factors involved in how a transistor works, and at which frequencies. The internal geometry of the '3866 is optimised for VHF and low UHF operation.

I've used them up in Band IV, paired as driver stages in link transmitters (for example) and - because it was a 28V device -it was ideal for use in my early 80's cheap VHF PA: A 2N3866 into a 2N3375, then into a 587BLY (a 28V aircraft transistor) - 100mW in for around 100W output. The whole amplifier strip cost about £15 in those days, and we used to build loads of them!

[radium98]

Thanks Albert H

[garada]

The 2N2219A is good for about 250 - 300mW at 100MHz and has been for 50 years!

The 2N2219A has different characteristics than the 2N2219 without "A" but it may also be that the manufacturer does not know what he is saying when he says that it is not valid for RF.

[radium98]

oH ONLY thanks garada. Never get attention for that .

[garada]

oH ONLY thanks garada. Never get attention for that .

Because you're a good person, but I'm not, so it's better to just keep quiet, thank you.

[radionortheast]

I used a 2n2219 in my power oscillator back in 1998, first transmitter I ever heard outside further away. I burned a few didn’t know about heatsinks, I remember them been used in smart kits, the 1w, then a 4w which probably had different transistors, I could never get either to work, we often send for replacements 2n2219, I kept the star shaped heatsink for ages.

I don’t think 2n2219 could be used as a drop in replacement on a veronica pll, with a simple oscillator alot of transistors will work but produce more or less power, you get the power oscillator, rf amplifiers it different, its been so long since I had any, 3866 could swapped for a 2n2247, they would often list on the instructions which could be used instead, 2n2219 would probably do the same as even smaller 2n2222 you could get from maplins, wouldn’t do much, I know I would often break them. I had 1w veronica kit I made years ago, you would get over a watt at higher voltage, it would lead to a shorter lifespan of the transistor.

[1608cc]

I got 0.6-0.8W from 2n2219 in one of my very first RF projects back in 2018, when attended to tech school.
Produced lot of heat even with a huge heatsink.

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