400W RF GENERATOR

[Stretchyman]

I have for sale some fully tested PCB's I made last year;

16Ch DDS, preprogrammed, selectable with DIP switch.

Quad GaN, latest FETs from Transphorm.

NCP81074 fast drivers.

90 % efficient, just needs bolting to a modest heatsink or metal case with small fan.

FETs have grounded tabs so no need for insulating washers etc.

PSU needs to be 48V @ 10A.(+12V@120mA for drivers)

I've had considerably more power from these with 600W @ 60V but things start to get a bit warm. At 400W it can be passively cooled.

ANY 200KHz band segment. (8MHz max)

I'll post up some pics on eBay but thought it best to advertise on here first.

$300 ONLY!

I can provide full instructions etc.

Has been heard in the air with good reports!

You will need your own modulator etc..

Str.

[Monophonia]

Interested to see pictures. I may be inclined to get lazy,

[Stretchyman]

Please mail me...

stretchyman2kATgooglemailDOTcom

[OgreVorbis]

I'm am interested in this transmitter, but I'm more interested to see the schematics than to buy it. I've learned I will always want more power and upgrades, and for that, it's better for me to understand the design first. Would you be willing to offer the schematics?

I'm also curious about the bandwidth of this design. Could a DDS module from ebay with 9850 and free tuning 2-30 MHz be used instead of channels? Of course, it probably can't go all the way to 30 MHz. You say 200 KHz segment, so it's narrowband (ie not balun match)?

[Stretchyman]

It's Class E and therefore narrow banded. Stop thinking about a Tx that covers the whole of HF, how are you going to switch the filters etc?
Single band designs make EVERYTHING so much simpler....

The genrator is 120x100 that's mm not inches!

Sorry I'm not willing to hand over the schematics, it's nothing special or different than any other design, just that I use modern parts.
The majority of work involves doing a decent PCB layout BTW.
I've spent over 2 years and £?? getting it right, I'm not just going to hand it over to you for nothing!
There's plenty of other designs on the net, why not use one of those, they may work!

Str

[Radio Station]

I'm am interested in this transmitter, but I'm more interested to see the schematics than to buy it. I've learned I will always want more power and upgrades, and for that, it's better for me to understand the design first. Would you be willing to offer the schematics?

I'm also curious about the bandwidth of this design. Could a DDS module from ebay with 9850 and free tuning 2-30 MHz be used instead of channels? Of course, it probably can't go all the way to 30 MHz. You say 200 KHz segment, so it's narrowband (ie not balun match)?

The problem with most of the  class E designs is it is limited to AM mode and is limited to no more than 8 MHz unless you use higher frequency more expensive MOSFET's

You can go to http://www.classeradio.com and get all the info you need on building one including parts. The newer design uses digital drive so you can drive it with a DDS VFO or drive it with a HF radio at about a watt of drive.

Also if you want the audio frequency response higher than 6 or 7 KHz audio you will need to change the values of the PDM low pass filter.

Personally I think it is better to have the ability to modulate both AM and SSB and other modes with the ability to go up from 160 to 10 meters.

[Stretchyman]

Close...

The PDM filter removes the clock and usually LPF's around 20KHz do won't effect your audio.

The simplicity and efficiency of a single band class E design is not to be underestimated.

A broadband design or such you speak is far more of a nightmare to construct. I'm not going to list all the issues.

You lot want to Tx on one frequency so why the xxxx are you wanting a design that covers the whole of HF? Just go and buy a SH ham radio.

I'm trying to make it simple whereas others seem to want to make it as complicated as possible!

Good luck chaps, I'm there already, have fun building your dream.

Str.

 

[Radio Station]

Close...

The PDM filter removes the clock and usually LPF's around 20KHz do won't effect your audio.


 

I am referring to Steve WA1QIX design. His is limited to about 7Khz audio since it is used for voice. He freely publishes his designs and encourages improvements,  He also will help anybody with building one.   

[Stretchyman]

I know the design, old as the hills (well nearly 10 years, a long time in technology)

Again... The 7KHz filter has nothing to do with PDM, it's to filter the audio.

The PDM filter is the MASSIVE toroid thing to filter out the (PDM) clock.

You've got a tad confused...

However all the facts on there are true and stand up well and are the basis for anyone starting to build these things.

However there's no point using obsolete devices and again no point using those bolt down drivers as you can drive modern fets with a SOIC driver at 5V with good efficiency.

I also hate that clip lead mess, yuck, why not just design a PCB like every other electronic device in the universe??

They wont be interested in helping you unless your a HAM BTW!

My design fits in the palm of your hand, no clip leads or ridiclus tuning caps etc

Str.

[Radio Station]

Steve is the designer he should know.

I am done arguing this with you.   

Who said anything about being a HAM. IF THAT IS WHAT IT TAKES IT IS A VERY CHEEP INVESTMENT and well worth it.

Sorry I might have caused you lost sales 

[Stretchyman]

Ha ha, nice one...

Keep tryin'

Nothing is lost, Nothing gained....

Str.