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THE AM BULLETIN BOARD => Class E Forum => Topic started by: vk3alk on April 18, 2020, 11:54:47 PM



Title: New 160M Transmitter
Post by: vk3alk on April 18, 2020, 11:54:47 PM
Since Pats unfortunate fire the activity on the Class E part of the forum will probably drop a bit so thought would post some pictures of my near finished Transmitter...
It only outputs appox 300 Watts but since the Australia legal limit is 120 Watts of carrier there is not much point running any more...
Has been tested running music audio for a number of hours and all seems good so way....
The test did pick up a poorly made Regulator Inductor ( thats my fault ) so had to make another using a slightly larger core...
All good now though....
Have attached a photo of the jig I use to make the transformers....

Are just waiting on some Manganin Wire for my Current Shunt to arrive and are labeling the meters used for Current  and SWR/Power...
Also need to makeup a SWR Bridge as well.
Tidy up some of the wiring and thats about it really...

Will still test more before transmitting on air though...


Wayne


Title: Re: New 160M Transmitter
Post by: N4LTA on April 19, 2020, 01:10:18 PM
Looks great.  Wish I could start on one like it. The appraiser starts tomorrow on my shop and lab. After he finishes, I start rummaging through to find what he missed. He seems like a good guy and I think I will be fine but I have no real ability to punch and cut metal and it will be a while until I can. I may try to build something using sendcutsend  laser cutters . They do a great job and are fast and not expensive..

Keep up the great work Wayne!

73

Pat
N4LTA


Title: Re: New 160M Transmitter
Post by: KD6VXI on April 20, 2020, 01:29:30 PM
Harbor freight sells a hydraulic punch set that goes from 3/4 to 2 inch.

Hunnerd bucks.

--Shane
KD6VXI


Title: Re: New 160M Transmitter
Post by: vk3alk on April 27, 2020, 05:43:05 AM
Ok its not the most exciting picture on the Forum but the TX is just about finished....
The flash of the camera hasn't quite done it justice as the paint color is darker and the labels have more detail....
Used the Meter program from Tonnes......a little mucking around but got there at the end of the day....
Just waiting on this wire for the Current Shunt to arrive so the TX has been pushed to the side .....
A little annoying waiting ..... the postage here at the moment is terrible...

Wayne..


Title: Re: New 160M Transmitter
Post by: N4LTA on April 27, 2020, 11:12:45 AM
Wayne

Looks very nice.

Pat
N4LTA


Title: Re: New 160M Transmitter
Post by: Opcom on April 30, 2020, 02:14:50 PM
Yes, very orderly and pleasing front panel. I like gray.


Title: Re: New 160M Transmitter
Post by: ua3ral on December 12, 2020, 11:15:42 AM
vk3alk
привет . :D
если Вас не затруднит ,скажите как Вы считали выходной трансформатор RF part  H-bridge . ???


Title: Re: New 160M Transmitter
Post by: vk3alk on December 12, 2020, 06:08:03 PM
Hi Yuriy

The transformer uses 2 or 3 FT114-61 cores .....
Have uploaded pictures of the winding....

Use 1mm ECW...

Twist the wires together and wind 6 turns through the cores....

One piece of wire goes to the H Bridge and the other 2 are connected in series and go to the LPF....

That makes the turns ratio 6:12 or 1:2 ..........

Hope that helps...



Wayne


Title: Re: New 160M Transmitter
Post by: ua3ral on December 13, 2020, 12:38:54 AM
 vk3alk .хорошо.
я так и делаю.
как считать индуктивность одной обмотки  ??? мкг  ???
надо 1600-1800 кгц .
в СССР свободные операторы делают  транзисторные АМ передатчики
частоты 1600-1800 кгц. 2900- 3200 кгц



Title: Re: New 160M Transmitter
Post by: vk3alk on December 13, 2020, 05:27:14 AM
Hi Yuriy....

Hope I am right with the translation...

The Transformer will work from 1.6Mhz to 5Mhz ....... using H Bridge Module ......

The inductance 6 turns is 2.4uH as the picture uploaded although now are using 3 cores .....


Wayne


Title: Re: New 160M Transmitter
Post by: ua3ral on December 14, 2020, 03:48:11 AM
vk3alk
Спасибо ! Удачи Вам !


Title: Re: New 160M Transmitter
Post by: vk3alk on December 14, 2020, 06:58:31 AM
 :) :)


Title: Re: New 160M Transmitter
Post by: vk3alk on December 30, 2020, 07:12:57 AM
Wasn't quite happy with the Heatsinking for the upper FET of the PWM.....
Was getting a little warm at around the 250 watt carrier fully modulated mark.......
After a bit of thought decided to mount the FETs under the PCB and bolt directly onto a larger Heatsink.....

The other photo shows the Heat Glue pumped into the ferrite cores etc:



Wayne


Title: Re: New 160M Transmitter
Post by: ua3ral on February 16, 2021, 06:24:07 AM
 vk3alk

 Hi Wayne

If possible could you post the waveform after the transformer GTD gate SiC FETS


Title: Re: New 160M Transmitter
Post by: vk3alk on February 16, 2021, 05:22:14 PM
Hi Yuriy

This is the one....

Can set my spare module up if that helps....

H Bridge requires 50% Duty Cycle on all FETs....


Wayne



Title: Re: New 160M Transmitter
Post by: ua3ral on February 17, 2021, 12:23:11 AM
Спасибо!!!


Title: Re: New 160M Transmitter
Post by: W1IA on March 04, 2021, 02:00:11 PM
Very nice work Wayne! I will have to take the time to read up on your work. Will have to listen to a websdr in the land down under. ;D Thanks for the nice e-mail. Back to the bench.

Brent W1IA
AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands