Messages

1

The RF Workbench / Re: 100W Linear PA for the FM Band

« on: October 23, 2020, 0947 UTC »

Could you point to one or two which you know are class A/AB/B. I guess the bias on Class AB/B could be tweaked to run it in Class A.

Thanks!!

2

The RF Workbench / Re: 100W Linear PA for the FM Band

« on: October 16, 2020, 0353 UTC »

Thanks for the reply, and no worries on the delay. I am grateful for this conversation. I think, to begin experimenting, I'll tone down my expectations. Instead of 10 carriers at 1W, lets say there are 6 carriers at 0.5W, so a total avg power of 3W, and a peak power of 9W.

I'll begin by looking at 10W class A designs, and then raising expectations from there. This would allow be to perhaps build a circuit of two of my own without spending many many $$$, and learn a thing or two about RF circuit design.

3

The RF Workbench / Re: 100W Linear PA for the FM Band

« on: October 11, 2020, 0405 UTC »

Could you point me to a link where such an amp is being sold. Most of what I can see online is in the 2m band. Thanks

4

The RF Workbench / Re: 100W Linear PA for the FM Band

« on: October 10, 2020, 0146 UTC »

Thanks for the reply. At this point, given the scope and place where this will be deployed, interference to other users won't be an issue, I have checked that.

What characteristics do you think their reference circuit has ..
https://www.nxp.com/products/rf/rf-power/rf-ism-and-broadcast/1-600-mhz-broadcast-and-ism/mrf101an-reference-circuits:MRF101AN-REFCirc

I see a place for Vgs bias, so perhaps there is some control over linearity?

Or maybe I should hunt for push-pull designs as you say (ClassA/ClassAB), but I would rather begin with experimenting with off the shelf available components given my limited RF design experience.

Any more pointers would be quite helpful!

5

The RF Workbench / 100W Linear PA for the FM Band

« on: October 09, 2020, 0737 UTC »

Hi folks. This is my very first post to this forum. I am a radio HAM based in the mountains in North India.

I am working on a project that involves using a SDR Radio to output multiple FM signals, and researching the power stage part of the design.

I need about 1W average per signal, and there may be upto 10 carriers, so 10W average Power. So this probably means an amplifier capable of upto 100W of output power. It also needs to be a linear amplifier.

I was wondering if anyone had pointers where I can start looking for designs I can build or purchase. I came across these reference designs based on the MRF101AN and wonder if they can do the job
https://www.nxp.com/products/rf/rf-power/rf-ism-and-broadcast/1-600-mhz-broadcast-and-ism/mrf101an-reference-circuits:MRF101AN-REFCirc

Thoughts?

73 // VU2TVE