Messages

601

For Sale / Wanted / Barter / Re: 4x16 Ch PIC controller for DDS. ANY FREQUENCY = NO MORE XTALS!

« on: December 14, 2015, 1806 UTC »

OK have settled on 2 banks of 16 Channels, 1 U.S. Bank and 1 Euro.

+ 2 more banks of 16Ch with M.W, 90m and ham freqs (any of these can be changed on request)

So I can offer a complete solution with DDS board and PIC.

Complete and programmed with these Frequencies;

EURO    US  
6200   6850
6205   6855
6210   6875
6240   6880
6245   6890
6250   6900
6260   6910
6265   6920
6270   6925
6280   6930
6285   6935
6290   6940
6300   6950
6380   6955
6390   6960
6400   6980

++++++


1476   5317
1850   7070
1885   7143
1933   7175
1945   7290
1963   7295
1972   8000
1985   11595
3229   12000
3395   13000
3615   14000
3625   14286
3705   18150
3825   21285
3870   21425
3875   10000


Output is 1V p-p sine or 5V square.

 

602

The RF Workbench / Re: Higher power design.

« on: December 11, 2015, 0902 UTC »

Inverting is same here, not sure what we're not saying to each other!!

Whether the amp is plugged directly into (U.S.) mains or run from a (110V) isolation transformer or from an inverted supply will ALL lead to the same voltage.

120V A.C. (or 110 or whatever)

This will be rectified and smoothed inside the amp to 120/150V D.C.

Cost is a bridge rectifier and a smoothing cap.

3 PSU's are way to big as the amp is not even as big as one of them!

Choice can be up to the end user.

The 110V isolation trannies are very cheap and safe enough and that would be my recommendation.

Str.

 

603

The RF Workbench / Re: Higher power design.

« on: December 11, 2015, 0718 UTC »

100/120V A.C. Dc'd should give 120/150V.

Limey builders use 110V tranny's on building sites and you lot have 120V

So one design can be powered direct from mains or inverted from 12/24V batteries to the higher voltage.

Covered in my first post  

Oh and..... Yes JP, Definitely Committed!

 

604

The RF Workbench / Re: Higher power design.

« on: December 10, 2015, 1517 UTC »

Indeed, a notable on here has enquired and I could REALLY not believe he was hauling round a Johnson (Viking?), massive batteries and an invertor to get on the air.

Kind of 'Inspired' me to come up with something more 'Modern'

That stuff is over 50 years old and testament to its design that it's still being used, but really....fine for 'Nostalgic' purposes but otherwise...FFS!

Who Knows having something more portable may make it more popular!

We'll see.

Soon!

Str.

605

The RF Workbench / Re: Higher power design.

« on: December 10, 2015, 1311 UTC »

NO, it wont do SSB as it's class E and not linear.

I'm not interested in SSB, fine for comms, crap for tunes!

Sure tho' the design uses parallel FETs, voltage however would be the same, you need lots of volts to keep the losses down.

More FETs = more current = more power however.

The parts are not that expensive, a FET pair can only be $20, it's more the time designing and testing + the meagre amount I will sell (50?) which will drive up the cost.

If someone said 'Build me a 100' that would halve the cost immediately!

Str.

606

The RF Workbench / Re: Higher power design.

« on: December 10, 2015, 0726 UTC »

Indeed, Price could be the problem as I was expecting to sell for £300 which is approx the same and at that price it would have to be a kit, building it would double the price.

How much power do folk really want? is always a question.

Soon as you go above a 10W carrier it means you can forget running from 12V and altho' I can get 25W carrier from a 24V supply even that's pushing it efficiency wise and its 10% better with 45V. So your going to need a mains/inverted supply.

May be able to do a 100W carrier (400W peak) for less? Would that be enough?

I notice folk on here aren't up to building much and while it's time consuming its fun but you do have to know what your doing!

Time is money as they say and I'm happy to recoup time spent designing and laying out PCB's from the sale of kits, building them makes them too expensive unless I do it for nothing, which frankly I'm not prepared to do (much!).

I'd definitely like to get some PCB's done for a higher power design but will only be able to supply kits.

We'll see.

Thanks for your input chaps.

Cheers from Blighty.

Stretchy.

607

Equipment / Re: Odd behavior from Ameritron Amplifier

« on: December 09, 2015, 1415 UTC »

NO Worries, Bud, but remember its a valve, they 'GLOW'........ Nicely!

 

You will get it working and in doing so will learn from the experience!

Most worthwhile!

 

Str.

608

The RF Workbench / Higher power design.

« on: December 09, 2015, 1132 UTC »

I’m still musing over a design for much higher power, 200W or 400W carrier which will yield 1KW or 1.5KW on peaks.
Of course this won’t be running from 12V and will need DC’d mains or inverted from a pair of rather large 12V SLA’s.
Please forget any notion of a design like this running from any voltage less than 110V-150V as the currents will be just too high and kill efficiency.
Keeping the volts high means less current (for the same power) and therefore less I²R loss.

Three versions; below 2MHz, 3-4MHz & 6-7MHz.

Size wise it should fit in 2U 19” rack and not weigh more than 10LBs or so.

What I’m interested in is how many people would be interested in such a design?

I’ve had some interest from one notable on here and am willing to put in some effort early next year as my lab will be ready and can give the project some priority.

So, 1 KW O/P min, PWM Mod (obviously), DDS channel selection of user programmable 32Chs, will have to have some kind of protection for over current and high SWR etc.

Ideas please.

Str.

609

Equipment / Re: Odd behavior from Ameritron Amplifier

« on: December 09, 2015, 0705 UTC »

DING!

That's the lightbulb coming on type noise BTW!

And Yes, twas I who recommended the Heater be checked glowing.

More time wasted.....

It's a valve and needs to have a glowing heater, so simple to check and as per a previous suggestion could well be the relay.

I think we're there now and think it probably could have taken a fair fewer thoughts.

Q, is Heater Glowing?

A, NO.

As per my previous suggestion check for 5V across the heater terminals of the valve.

No scary voltages on the valve base so you should be OK.

OK!

610

Equipment / Re: Odd behavior from Ameritron Amplifier

« on: December 08, 2015, 1717 UTC »

Cool, no worries 

Mr Farley's reply is a good one....

That's it for tonight from me, you have enough info, you're going to have to measure stuff now.

Good Luck!

Str.

611

Equipment / Re: Odd behavior from Ameritron Amplifier

« on: December 08, 2015, 1649 UTC »

OK well you have VOLTS but NO CURRENT.

However you still have to make sure the volts are getting to the tubes ANODE, that's the top connection and with close to 3KV on it your going to have to be careful you don't touch it.

There are two chokes that could be O/C and stopping the volts reaching the anode.

Just get a meter that will measure such a voltage and measure it. Probably best to get someone else to do that.

You could also turn it off (you have to make sure the PSU is completely discharged) and buzz out this connection. Again get someone else if your not sure.

I want to help and not be responsible for your demise!

3KV is VERY dangerous, I cannot emphasise that enough!

The HEATER also needs 5V at lots of amps and probably glows a bit (you can see in a darkened room).

Provided both voltages are present you should get current flow and if you don't the valve is shot.

BTW I did ask if the switch read HT and IG, you said NO, should have been YES I believe, HT, PLATE, V all the same BTW as IG is Ig is it not?

Kind of thought you maybe had a different amp for mo!

Would have saved some time......

We'll get there.....


Eventually.

612

Equipment / Re: Odd behavior from Ameritron Amplifier

« on: December 08, 2015, 1531 UTC »

Yes OK PLATE VOLTAGE

What does it read.

 

+ send a shortcut to a picture of the EXACT model of your amp as all the ones I can see read 'Ig' too.

613

Equipment / Re: Odd behavior from Ameritron Amplifier

« on: December 08, 2015, 1421 UTC »

Quite simple then.......................

If it's not taking any current the valve is NOT working.

Not too difficult to work that one out!!

OK, could be many things and as the manual suggests, the valve or socket or anything actually as the amp is just, simply a valve oh and a power supply too.

Has the meter (the one on the amp) got 2 other positions to indicate H.T. and I.G?

What do they say?

 

614

Equipment / Re: Odd behavior from Ameritron Amplifier

« on: December 08, 2015, 0741 UTC »

Ham radio, Old Guys, Yep I'm here already 

Ha! 

Re the 'Over modulation' you should be tuning it up with an unmodulated carrier BTW! (I'm sure you are)

You don't have to 'aspire' to be anything either, I'll help coz your into RADIO, that's enough for me!!

Str.

615

Equipment / Re: Odd behavior from Ameritron Amplifier

« on: December 07, 2015, 1641 UTC »

OK, that photobucket site not good, I cant even zoom into the image, maybe it's just my O.S. (android)

OK it looks like some crappy (sorry) CB thing, hmm, not to be trusted and your not on 27MHz so wont be accurate on 6MHz.

OK plug another radio in there and see if it works, any old .... a CB, anything, does the meter respond normally?

OFF now see you tmrw.

Str.