Messages

121

Equipment / Re: Looking for Linear Power Supply

« on: March 10, 2021, 1827 UTC »

Commonly available 24V smpsu's all over eBay.

If you think they're manufactured in any other place than CH, think again! They aren't made in the US..

Despite the bad rep it mainly down to ignorance as they are in the main absolutely fine.

Try and stick with a branded version like; JCPOWER or MEANWELL.

Just parrallel up what you need 3x500W or 2x750W or whatever.

24V will adj down to 18V.

Btw, you're looking for a power supply for your linear, not a linear power supply as that's an analogue, i.e. not switching lump with a massive transformer etc.

Str.

122

The RF Workbench / Re: Someone had Corsair II AM TX experience?

« on: February 14, 2021, 1154 UTC »

How wrong you are...

123

The RF Workbench / Re: Stretchyman 40 W TX Reliability Modifications

« on: February 14, 2021, 1153 UTC »

Yeh, he's being such a TW*T

Just ignore...

124

The RF Workbench / Re: Someone had Corsair II AM TX experience?

« on: February 13, 2021, 1800 UTC »

Just check "Simplest Tx" post on here.

To modulate just use the class D amps mentioned.

Super simple!

Str.

125

The RF Workbench / Re: Someone had Corsair II AM TX experience?

« on: February 13, 2021, 1751 UTC »

With any decent design using a PCB is by far the best method and sure they used to be expensive but now not so. Shame as I've just given away 20+ LuLu PCBs to a UK chap and don't have any left.

Also the main 'problem' is to how you're going to generate the frequency you want in the first place.

So may I ask, what method do you intend to use?

Str.

126

The RF Workbench / Re: Someone had Corsair II AM TX experience?

« on: February 13, 2021, 1245 UTC »

So a design that uses less parts (still commonly available) and is more efficient etc gets less attention? Doesn't make sense, apart from the fact it's got some kind of web/utoob kudos. I guess it's the internet generation....

There's so many designs for stuff like this around and 99% would never work without decent layout etc and was the only reason I ever designed a PCB

The class D mod amps are great, bought 100 a few months ago direct. Shame they no longer have the space for the regulator and the front end has a really dumb response, most strange, easily sorted with a few simple component changes.

Details are available..

Str.

127

The RF Workbench / Re: Someone had Corsair II AM TX experience?

« on: February 12, 2021, 2152 UTC »

Just depends on how you drive it, squarewave = class E, sine =C, sure there's more to it as the o/p has to be bandpass but still the quicker the switching the greater the eff% pure and simples.

Str.

128

The RF Workbench / Re: Someone had Corsair II AM TX experience?

« on: February 12, 2021, 1928 UTC »

Run from 12/14V 4W us about right with 6V on the  RF stage at carrier. Good if you could show the drain and gate waveforms. Folk moan about class E as you really need a scope to see the drain waveform but in reality you can tune it with your finger as when it's cool it's working the best!

I've published the values for normal class E operation on here in an older post so very simple to replicate.

Str.

129

The RF Workbench / Re: Someone had Corsair II AM TX experience?

« on: February 12, 2021, 1642 UTC »

It's not the best design and have no idea why it gets so much attention.

The LuLu PA stage is class E and this is AB and is just going to generate more heat and be less efficient. It's also way more components and you've got to set up the bias correctly etc.

Very old design...

Class E is hardly new either and has been around since 1977, best to use it as it's by far the best method for simple narrow band transmitter stages.

Str.

130

For Sale / Wanted / Barter / Re: New Line of Transmitters from Stretchyman.

« on: February 11, 2021, 1547 UTC »

Best to PM or email..

131

The RF Workbench / Re: Stretchyman 40 W TX Reliability Modifications

« on: February 11, 2021, 0932 UTC »

Just to be clear before you slag me off anymore.

The very first ever design I made was an unashamed copy of the venerable LuLu design. Fat better than any other design to date and I must emphasise not my design. All I ever did was make a PCB to make replication a simple matter.

It uses a Xtal which I had to get made at considerable cost (£14 ea.) and managed to get quite a few units made (100 approx).

That was five years ago and all designs since 2016/17 have an AD9833 DDS.

At the time of the first design I was unable to find anyone to write SW to program the DDS but since finding someone and now having the SW it's a no brainer to use and the DDS's are $2 and will prog to any freq upto <12MHz.

There is absolutely no reason why anyone would use a Xtal anymore and even the programmable oscillators for Cardinal are far superior and are perfect for single channel use.

I still suspect most 'simple' Xtal controlled designs to exhibit some form of FM that's visible on an SDR.

So as I must say again it's not my design, however  there are other designs out there that are and Yes you've slagged those off as well....

I'll continue to improve my designs and learn from any mistakes made, I hope they are few and seem to have many happy and repeat customers.

I look forward to seeing any design from particularly yourself or anyone else for that matter that you mass market and build 100+ units.

I doubt (know) that this will ever happen.

I look forward to your reply.

Str.

132

For Sale / Wanted / Barter / Re: New Line of Transmitters from Stretchyman.

« on: February 09, 2021, 0807 UTC »

I'm no longer allowed to advertise on here 
so best to PM or email me at;

stretchyman2k@googlemail.com

For further info.

Cheers

Stretchy.

133

North American Shortwave Pirate / Re: Yeah Man Radio 6925.1 AM 2116 UTC 6 Feb 2021

« on: February 06, 2021, 2209 UTC »

TURN IT UP!

Get that Red light flashing!

Str.

134

Equipment / Re: BCD436HP CB reception tells me I'm on a diff freq

« on: January 26, 2021, 1252 UTC »

'Old' CB was 23 Ch, 'New' CB is 40ch, may have something to do with it? Just a guess.....

Str.

135

Group W Bench / Re: Empty HF frequency band for emergency coms

« on: January 21, 2021, 1831 UTC »

We don't have to worry in the UK all the bombs will fly over our heads. Definitely an advantage living on an island and.....we all get on with each other!

Personal freedom, too much space and guns was never going to work.....

 

Str.