We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Author Topic: SSB driver 1KW FET Linears  (Read 2549 times)

Offline Stretchyman

  • Hero Member
  • *****
  • Posts: 655
    • View Profile
SSB driver 1KW FET Linears
« on: December 12, 2019, 1852 UTC »
Just to guage the interest or otherwise....

I'm toying with the idea of designing an ssb driver (5W) to drive the monster linears using the BLF188XR.

I'm aiming for decent quality, no ne602 rubbish.

8 pole filter and -50dBc for carrier, however b/w will be 7.5KHz for nice w-i-d-e audio.

Your thoughts please.

 :)

Str.
'It's better to give than receive' so why Rx when you can Tx!

                                              ;)

Offline redhat

  • DX Legend
  • ******
  • Posts: 1585
  • USA
  • Music is my drug.
    • View Profile
    • Email
Re: SSB driver 1KW FET Linears
« Reply #1 on: December 15, 2019, 0929 UTC »
How are you planning to generate the SSB, phasing or filtering?

+-RH
Somewhere under the stars...
Airspy HF+, MLA-30/Mini-whip/Chi-Town Loop
Please send QSL's and reception reports to xfmshortwave [at] proton [d0t] me

Offline Stretchyman

  • Hero Member
  • *****
  • Posts: 655
    • View Profile
Re: SSB driver 1KW FET Linears
« Reply #2 on: December 15, 2019, 1134 UTC »
Thanks for the post...

So....Mixing initially.

AD831 and 8 pole 7.5K wide filter etc.

However I'm happy to experiment.

As with any product it will be the simplest and best implementation I can find.

I'm open to suggestions!

Regards

Stretchy.
'It's better to give than receive' so why Rx when you can Tx!

                                              ;)

Offline JimIO

  • Sr. Member
  • ****
  • Posts: 491
  • QTH I.O. MA
    • View Profile
Re: SSB driver 1KW FET Linears
« Reply #3 on: December 15, 2019, 1707 UTC »
7.5khz is overkill for  "thump thump" and SSTV    8)

~

Offline redhat

  • DX Legend
  • ******
  • Posts: 1585
  • USA
  • Music is my drug.
    • View Profile
    • Email
Re: SSB driver 1KW FET Linears
« Reply #4 on: December 16, 2019, 2222 UTC »
I disagree.  I'll take all the bandwidth I can get, up to 15KHz.

+-RH
Somewhere under the stars...
Airspy HF+, MLA-30/Mini-whip/Chi-Town Loop
Please send QSL's and reception reports to xfmshortwave [at] proton [d0t] me

Offline ChrisSmolinski

  • Administrator
  • Marconi Class DXer
  • *****
  • Posts: 31106
  • Westminster, MD USA
    • View Profile
    • Black Cat Systems
Re: SSB driver 1KW FET Linears
« Reply #5 on: December 16, 2019, 2331 UTC »
I know redhat and several other ops disagree with me on this, but... IMHO any transmitted spectral content over about +/- 6 kHz (if you have an SIO 555 signal), and down to about +/-3 kHz for the average reception quality of a pirate, is wasted energy.   :P
Chris Smolinski
Westminster, MD
eQSLs appreciated! csmolinski@blackcatsystems.com
netSDR / AFE822x / AirSpy HF+ / KiwiSDR / 900 ft Horz skyloop / 500 ft NE beverage / 250 ft V Beam / 58 ft T2FD / 120 ft T2FD / 400 ft south beverage / 43m, 20m, 10m  dipoles / Crossed Parallel Loop / Discone in a tree

Offline Stretchyman

  • Hero Member
  • *****
  • Posts: 655
    • View Profile
Re: SSB driver 1KW FET Linears
« Reply #6 on: December 17, 2019, 0559 UTC »
The filters, if I use that method are +/-3.75 8 pole and very reasonably priced.

Most A.M. Rx filters are 6KHz, hence my decision.

Str.

'It's better to give than receive' so why Rx when you can Tx!

                                              ;)

Offline Azimuth Coordinator

  • Full Member
  • ***
  • Posts: 247
  • Listen for Us on 4185 Khz or 5185 Khz
    • View Profile
    • Email
Re: SSB driver 1KW FET Linears
« Reply #7 on: December 17, 2019, 1709 UTC »
Quote
I know redhat and several other ops disagree with me on this, but... IMHO any transmitted spectral content over about +/- 6 kHz (if you have an SIO 555 signal), and down to about +/-3 kHz for the average reception quality of a pirate, is wasted energy

Of Course I'm more Esoteric but I'm in the Belief that  You should transmit the best quality signal / audio for your listeners. I think it makes for a more enjoyable broadcast  I run 20hz -10khz audio but I have the ability to run full 20 - 20khz  If the listener has the ability to hear full bandwidth audio I'm sure they would like to.  If not they can decide on how much filtering is needed.  I have many reports sent to me that included an audio clip of the show and most are very enjoyable to listen to.  So Why Not if you can. 

BTW...   AM is the standard.. SSB is a compromise..  The key is the signal not be fatiguing 

tAC
QTH: A Clandestine location on the East Coast
Watkins Johnson WJ-8716, WJ-8718A, WJ-8618B
Radio.Illuminati6150@Gmail.com

Offline JimIO

  • Sr. Member
  • ****
  • Posts: 491
  • QTH I.O. MA
    • View Profile
Re: SSB driver 1KW FET Linears
« Reply #8 on: December 17, 2019, 1829 UTC »
I've looked at some description of how phasing SSB works and can't see how it could work very well if at all for music. Are the descriptions too simple or what?

~

Offline redhat

  • DX Legend
  • ******
  • Posts: 1585
  • USA
  • Music is my drug.
    • View Profile
    • Email
Re: SSB driver 1KW FET Linears
« Reply #9 on: December 17, 2019, 1918 UTC »
Phasing SSB is nothing more than a pair of balanced modulator fed with I and Q carriers and modulating signals that are 90 degrees out of phase.  The audio is passed through two all-pass networks to derive the required phase delay.  It used to be that the carriers were derived by passing the RF carrier through a 90 degree phase shift network.  This doesn't work over a wide range of frequencies, and it better solved today by using DDS chips with sine and cosine outputs.  The audio phase delay networks are the only thing that really limits your audio bandwidth, and implementations up to 20 KHz are not uncommon.

I echo the sentiments of AC above.  I set the transmission bandwidth for my enjoyment.  The listener can choose how much they want to hear.

+-RH
« Last Edit: December 17, 2019, 1932 UTC by redhat »
Somewhere under the stars...
Airspy HF+, MLA-30/Mini-whip/Chi-Town Loop
Please send QSL's and reception reports to xfmshortwave [at] proton [d0t] me

Offline Stretchyman

  • Hero Member
  • *****
  • Posts: 655
    • View Profile
Re: SSB driver 1KW FET Linears
« Reply #10 on: December 17, 2019, 2015 UTC »
Yes AC, I've got A.M. done but I'd still like to put out a product to drive the BLR family, makes for a very simple KW SSB setup and I can already use a 5W AM. Tx to drive them for A.M.

I've still to sell anything to any Ham, altho' they are not my priority I wouldn't mind another market to generate more sales.

Regards.

Stretchy.
'It's better to give than receive' so why Rx when you can Tx!

                                              ;)

 

HFUnderground T-Shirt
HFUnderground House Flag
by MitchellTimeDesigns