Brian needs more power... any suggestions ?

[sinus trouble]

I shall repeat!

There is an excellent 300W amplifier which is available with DRIVER STAGE and protection built in!
If you email the supplier, they may even build and test it for you? (As you are not in the UK)

Yes it has a driver stage built in! Input power is 0.5 to 1 Watt!

Currently it is DIY! But as i mentioned previously! If you email the supplier, they MAY build and test it for you!

OK..... yes I seen you replied with this before but......
Do I have to guess who the supplier is

Yes!! You only have 3 guesses then your time is up!

Only jokes! Links below!

[sinus trouble]

https://www.enigma-shop.com/component/h ... the-blf278

[sinus trouble]

https://www.enigma-shop.com/component/h ... ier-module

[sinus trouble]

Again, these are just suggestions!

I do not know if it complies with Canary Islands regulations? Or if it is something of interest to you?

I can assure you that it will be top notch gear!!

Either way? Its worth an Email or two!

[BriansBrain]

Again, these are just suggestions!
I do not know if it complies with Canary Islands regulations? Or if it is something of interest to you?

Thanks for the links = interesting reading BUT...
The first link ''using the BLF278'' they quote = Efficiency 68-78% (73% typical)
Second link ''High Power 300W'' they quote = exceeding 70% (typically 75%)
However on the same page quote: Current draw: Typical 9A at 48V thiis = 432W @ 300W RF out = 69% Efficiency

Add the power for some fans, the Exciter and other stuff.
Then you have to calculate the Efficiency of the 48V power supply.
And add on another 15V power suppy for the other stuff.
Overall TOTAL Efficiency will be down to less than 65%

[BriansBrain]

I do not know if it complies with Canary Islands regulations? Or if it is something of interest to you?

Just to confirm what I mean regarding efficiency...
Say... just the RF amp board runs at 70%
A 48V 30A 1500W power supply at 80%
Conclusion 70 x 80 = 5600 / 100 = TOTAL efficiency= 56%

48V 30A 1500W Efficiency.jpg

[rigmo]

However on the same page quote: Current draw: Typical 9A at 48V thiis = 432W @ 300W RF out = 69% Efficiency

Add the power for some fans, the Exciter and other stuff.
Then you have to calculate the Efficiency of the 48V power supply.
And add on another 15V power suppy for the other stuff.
Overall TOTAL Efficiency will be down to less than 65%

You made me open my old PC box with MRF151G (it's better than BLF278) min. Good match 300W RF power @ 48V 8A with 200mA idle BIAS (most of them say 100mA per side..) haven't touched it since I got it in 2018
Please do not count the fans in the performance of one amplifier.. it can only be added to the cooling losses because 93W goes to heating...
use solar panels 300w or 600w and drive exciter and cooling (12V)... the investment is more less than the whole year for broadcasting...

[rigmo]

MRF151G PCB and BLF278

[mikroman]

good old elico. still have one, for years on duty without a day off on tricky location.

[sinus trouble]

I do not know if it complies with Canary Islands regulations? Or if it is something of interest to you?

Just to confirm what I mean regarding efficiency...
Say... just the RF amp board runs at 70%
A 48V 30A 1500W power supply at 80%
Conclusion 70 x 80 = 5600 / 100 = TOTAL efficiency= 56%

48V 30A 1500W Efficiency.jpg

NO! It does not work like that!

You are basing all the different functions of your complete setup on a single RF output!

Yes! Power consumption will increase exponentially the more you upgrade, but efficiency remains the same!

For example

If your PSU is 80% efficient, exciter is 80% efficient and PA is 80% efficient!

System efficiency = 80%

If you are looking for more than that? Keep dreaming! Nothing comes for free!

[sinus trouble]

Infact!

Your cooling system most likely consumes more power than your exciter!

If you really want to save energy/money and feel inventive? You could even explore water cooling by integrating heatsinks into your residential system?

Thermal efficiency could work in your favour just as well as electrical efficiency!

[Albert H]

I did a lot of work on very high efficiency AM some years ago, for the Designs Department of a Big Broadcasting Concern.

Traditional ways of generating AM ("Anode" or "Heising" modulation) gives - at best - ~25% efficiency. Moving to cleverer ways of producing AM ("Doherty" or "Cheirix" designs) can increase efficiency to around 65% (if you're lucky) at the expense of massively more complex transmitter circuits, more tricky alignment, more interaction with the antenna match.... and so much more!

The next step was to move to PWM means of generating AM. Using Class E amplifiers (~93% efficient) and "outphased" PWM, we developed a transmitter that achieved the dizzying heights of 78% efficiency. Add in the cooling plant consumption, and the inefficiencies of AC mains to very smooth DC power supplies, and we were at about 70% efficiency. This has NEVER been beaten by any AM transmitter design or configuration.

When it came to FM transmitters, the first issue is the smoothness and cleanliness of the DC supplies - Switched-Mode Power Supplies need not apply - they are NEVER sufficiently clean for critical FM use, and only win in terms of weight. When it comes to efficiency and electrical purity, they're dreadful! The power supplies we used were based on specially wound toroidial types, with additional secondaries for the exciter, the audio processing / stereo coder and to drive low voltage fans. The intrinsic efficiency of our FET power amplifiers was around 80%, but when everything else was taken into account, the RF out was about 55% of the mains power input with everything absolutely optimised. Short of inventing perpetual motion (or contradicting the Laws of Physics) there's no way to improve on this.

If you want to run 500 Watts up the coax, you're going to consume around 1 kW in the Real World™. Nobody has ever bettered this kind of efficiency figure. If you're able to re-engineer the station antenna, you can double your effective radiated power at no increase in mains consumption, but you're either unwilling or unable to do the antenna engineering. This is the only approach that will give you a power increase without increased power consumption. There is no other option. If you're going to continue with your +2.1dBd aerial gain, your overall station efficiency will always be around the 60% mark at best, irrespective of the power of the transmitter.

[rigmo]

good old elico. still have one, for years on duty without a day off on tricky location.

if you need I cn get you more then 10pcs I need to see

[mikroman]

I have a boxed unit PA300. If it fails, I'll keep it in mind!

[BriansBrain]

NO! It does not work like that!

You are basing all the different functions of your complete setup on a single RF output!

Yes... I am talking about the ''Overall Efficiency'' of the TX system.
Compared to an Elenos Professional Transmitter that quotes...
An overall average of 71% up to 74% certified efficiency in the FM band.

Then...

If your PSU is 80% efficient, exciter is 80% efficient and PA is 80% efficient!
System efficiency = 80%

Try again...
if PSU is 80% efficient, and PA is 80% efficient.
So... 80 x 80 = 6400 / 100 = 64% Total Efficiency

[BriansBrain]

The intrinsic efficiency of our FET power amplifiers was around 80%, but when everything else was taken into account, the RF out was about 55% of the mains power input with everything absolutely optimised. Short of inventing perpetual motion (or contradicting the Laws of Physics) there's no way to improve on this.

Thanks you clarifying the ''Real'' meaning of efficiency for those on this forum that do not understand what I was trying to put across.

If you want to run 500 Watts up the coax, you're going to consume around 1 kW in the Real World™. Nobody has ever bettered this kind of efficiency figure.

Sorry to correct you mate but your wrong

Google the Elenos ETG500.5 500W FM transmitter

INSTALLATION REQUIREMENTS
Power supply 110, 230 Two-Singlephase Version 50-60 Hz VAC
Power consumption (typical) 690 W
Current consumption (typical@230 V) 3 A
Overall efficiency (typical from -3 dB
to Pnom)
> = 70%

If you're going to continue with your +2.1dBd aerial gain, your overall station efficiency will always be around the 60% mark at best, irrespective of the power of the transmitter.

Please read above

Regards to my Brian @ 16.5 hrs a day and a required 500W RF up the antenna cable...

A 60% efficient transmitter will consume 833W from the Mains Electric
16.5 x 833 = 13,7 kWh per day = 5000 kWh x €0.27 kWh cost = €1350 per year.

A 70% efficient transmitter will consume 714W from the Mains Electric
16.5 x 714m = 11.8 kWh per day = 4307 kWh x €0.27 kWh cost = €1162 per year.

I have been running Brian now for 4 years and would expect to do the same with a 500W

That would = €752

.

[jvok]

Brian - I think you've answered your own question. If energy costs are the driving factor, you can't/won't put up a higher gain aerial, and you don't think you can beat the Elenos on efficiency with a DIY rig, then buy the Elenos and be done with it.

[jvok]

That said I think the main reason for your low efficiency numbers is that youre looking at a cheap shit no-name PSU from ebay. If you look at reputable brands like Meanwell, XP Power and TDK-Lambda, they all have ~90% efficiency. The difference between 80% and 90% is massive when you start cascading efficiency numbers like that.

An 80% efficient PSU with a 70% amp gives overall 56% efficiency
A 90% efficient PSU with a 70% amp gives overall 63% efficiency
An 80% efficient PSU with an 80% amp gives overall 64% efficiency
A 90% efficient PSU with an 80% amp gives overall 72% efficiency

Minus losses for exciter, fans etc but at these power levels those will only eat a couple of % from your total.

Now you'll pay a lot more money for a good PSU compared to what you pay on eBay, but as you've already worked out, it's worth it once you factor in energy costs. And if you're willing to pay £7k for the Elenos then I don't see why you wouldn't pay a bit extra for a better PSU.

At the end of the day all Elenos are doing to get such good efficiency numbers is pairing an efficient PSU with an efficient amp. There's no magic here, and if they can do it there's no reason why you can't do it too. Or maybe you decide it's not worth the effort and you'd rather just pay the premium to let Elenos do it for you. Either option makes sense, it just comes down to your priorities.

[Albert H]

If you want to run 500 Watts up the coax, you're going to consume around 1 kW in the Real World™. Nobody has ever bettered this kind of efficiency figure.

Sorry to correct you mate but your wrong

Google the Elenos ETG500.5 500W FM transmitter

INSTALLATION REQUIREMENTS
Power supply 110, 230 Two-Singlephase Version 50-60 Hz VAC
Power consumption (typical) 690 W
Current consumption (typical@230 V) 3 A
Overall efficiency (typical from -3 dB
to Pnom)
> = 70%

Elenos were always a bit "economical" with their quoted figures. Their 500W box was meant to have second harmonic of -60dBc. I've measured one into a dummy load, and they achieve -42dBc at best. Their in-band noise is horrible, and their "efficiency" figures should win a Booker Prize for Fiction. They're desperate to sell their rubbish.

For just €85 more, you can get a Siel 500W box that has a real second harmonic content of -71 dBc, no measurable other harmonic products, and the first adjacent noise floor (ie: +/- 200 kHz from the nominal carrier frequency) is about -98dBc (very close to the limit of my analyser noise floor, so +/- 1dBc). The Siel effort has a measured overall efficiency of 57% - typical for gear of its type.

The Bext offering in that class manages just 52% efficiency (for a circuit very similar to the Siel box). A couple of other manufacturers offer overall efficiencies of around 50%, and this is considered pretty good in the industry.

You really do need to look at antennas with gain!

[sinus trouble]

Some excellent points form Jvok, Albert and yourself!

I am often sceptical of large manufacturers inflating expectations!

I did research the ETG1000 specifications, They mentioned the use of "ICEFETS" A new revolution!

Sadly, i did not find any useful data on these devices?? (Maybe highly classified info)

Anyways as mentioned! It seems to be your only option?

Let us know how you get on!