Who reconized this RF Power Amplifier?

[Marcel]

Who recognized this RF Power Amplifier?

I would like get some more data before connecting it.

[RF-Head]

yes it's mine
Real old design with micro for SWR en Temp protection
Amp is a copy of the warnerRF 150W amp

[radium98]

remember be BW 150

[teckniqs]

remember be BW 150

The BW 150w amp is 24v with SD1407, not 48v with BLF177....

[Albert H]

Those boards (or ones very like them) were available in the US through "Progressive Concepts" and Bext had a PCB just like that in one of their 3U 19" 100W drivers.

[radium98]

I said remembering me , because it is very closed ,yes this is a mosfet the other is bipolar 30 mz and used in fm how starnge that sdxx

[RF-Head]

I made this and still have the layout over here
It's not a BW of other amp
later version didnt use the stepdown regulator on the board

[Electronically]

remember be BW 150

The BW 150w amp is 24v with SD1407, not 48v with BLF177....

Yup they boards are 24v correct

Sent from my AMN-LX9 using Tapatalk

[Electronically]

remember be BW 150

The BW 150w amp is 24v with SD1407, not 48v with BLF177....

Yup they boards are 24v correct

Sent from my AMN-LX9 using Tapatalk

Do you know something a mate of mine has this board he says you need 25 Watts to run that. Surely not

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[teckniqs]

Surely not

You are correct, surely not indeed.

.....If your friend has put 25 to 50+ times the amount of required drive into this board then he has got a dead board!!

As far as I know the drive for H's board is around either 300mW, 500mW or 1W.

[yellowbeard]

SD1407 does take about 15 or 20 Watts to drive it to full power, BW used a BLF244 buffer on those amps, input power 0.5 - 1 Watt. An SD1407 on its own might require 25 Watts depending on the circuit. It's an old smokey transistor now, but that was savage gain when it came out first.

[Bton-FM]

Surely not

You are correct, surely not indeed.

.....If your friend has put 25 to 50+ times the amount of required drive into this board then he has got a dead board!!
As far as I know the drive for H's board is around either 300mW, 500mW or 1W.

It must be ~300mw since there is an RD06 before the BLF177.

...I dread to think of what would happen to an RD06 if you put that much power into it! Some magical smoke at least that’s for sure!

[radium98]

thank you yellowbeard in fact yes . with 1 or 10 k at bias od blf244 if i am not mistaken .

[Electronically]

Surely not

You are correct, surely not indeed.

.....If your friend has put 25 to 50+ times the amount of required drive into this board then he has got a dead board!!

As far as I know the drive for H's board is around either 300mW, 500mW or 1W.

I thought the same thank you teckniqs for clearing that up.

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[Electronically]

SD1407 does take about 15 or 20 Watts to drive it to full power, BW used a BLF244 buffer on those amps, input power 0.5 - 1 Watt. An SD1407 on its own might require 25 Watts depending on the circuit. It's an old smokey transistor now, but that was savage gain when it came out first.

Spot on yellow board

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[teckniqs]

SD1407 does take about 15 or 20 Watts to drive it to full power, BW used a BLF244 buffer on those amps, input power 0.5 - 1 Watt. An SD1407 on its own might require 25 Watts depending on the circuit. It's an old smokey transistor now, but that was savage gain when it came out first.

You are absolutely right in saying this and I would have mentioned this if he didn't just say "board" and said "the final output device".

.....From what I am aware BOTH "boards" are around 300-1000mW drive.

You certainly wouldn't want to put 25w into a BLF244 which is the driver of the BW amp or put 25w into an RD06HVF1 which is far more than what the "board" is designed to be driven with.

[Marcel]

Thanks for all the comments.
It will require about 300 mw of input in this setup without an input attenuator.

What makes me less happy is the low pass filter which can really perform a lot beter, the in band attenuation is way too high.

[Marcel]

Due to the lack of shielding between the filter sections, the harmonic attenuation from the 3rd harmonic can also be better, but in principle this is also sufficient.

What strikes me is that it often all well designed but the actual implemtation is quite lacking.

In this design I miss the shielding, the coils are too close to the PCB (lowers the Q factor) and there is a lot to be gained in the ceramic capacitors used.

If you look for other post between me (Tue Apr 28, 2020) will come across the design of a simple low pass filter which works much better because I have adhered to a few simple rules.

[XXL]

So filter coils should be raised a few mm above the board ?

[Marcel]

About 8MM, but it is also important that the coils are not too close to the shield and that there is sufficients distance from each other.

Tried everything but <<DISTANCE>> is one of the important things.