Suggestion: PCI MAX – Up the power

NikosE · Post by **NikosE** » Mon Mar 25, 2002 8:11 pm

Here is a suggestion for a new product in the PCI MAX series, which would boost the power output of the PCI MAX card. Comments from other PCI MAX users or potential users are welcome. You never know; if there is sufficient interest, Marko may consider realising this project

The PCI MAX is a great concept (PC integration) and a high quality exciter/microTx. Many people will find that its power output (0.4W) is sufficient for their purposes, but some others would like to get that extra bit of juice out of it (obviously I belong to the later group).

PCS Electronics offers a 5W RF amplifier to boost the power of the PCI MAX and that maybe fine, however, the same degree of integration with the PC that the PCI MAX card provides, doesn’t apply any more; this 5W amplifier is not integrated within the PC.

I would like to see a new product in the PC MAX series, the PCI MAX “Booster”. This would be a PCI card, 2-3W linear RF amplifier, which could boost the signal of the PCI MAX using the same principles of PC integration. The software control for the amplifier could be via a dedicated driver or an additional option to the existing PCI MAX driver that would allow the switching on/off of the amplifier and even vary the amplifier’s power level. The pricing should be close to the price of a PCI MAX card.

Technically, the amplifier should amplify the PCI MAX signal with minimal distortion, include parasitic suppression, would not cause undesirable effects to the operation of the PC, would not require manual intervention (e.g., tuning) and when “switched off” should allow the nominal PCI MAX output signal to go through it without suffering significant reduction.

So what about it folks? Post your reactions, counter suggestions and ideas in this forum!

Guest · Post by **Guest** » Tue Mar 26, 2002 10:54 pm

I feel the PCI Max is good as-is, if power out was 1 watt a few more options would be possible. no need for 2 or 3 watts, build a
great antenna first!

Range is 1 mile+ at 1 watt power level. If you want more range, get an HTA 20 brick amp from Ebay and "mod" it yourself. You will have about 28 to 32 watts out, and a range up to 10+ miles on flat terrain if cars are your audience.

"Warning"

Before you go to higher power levels, spend alot on a good antenna & use a great low pass filter like PCS sells. A friend built a slim-jim mounted 40' high, runs ISAMAX 1 watt with an HTA 20 amp. Range is up to 15 miles, to cars.

Remember this truth, what 2 or 3 watts can do with an antenna at 20' or 25', a good slim-jim with 1 watt at 40' will win "hands down" every time. Extra coax and antenna mast are cheaper than amplifiers...

NikosE · Post by **NikosE** » Sat Mar 30, 2002 10:47 pm

Hi “Anonymous”,

Even though I agree with your statements concerning the importance of the aerial system with respect to the transmission range, I think that you missed my point.

The PC MAX series is unique because it is integrated within the PC and the FM exciter is under software control. To my knowledge, there are no other FM exciters / RF amplifiers in the market and in the given price range that offer this degree of functionality. My suggestion for the introduction of a PCI MAX “booster” was based on the idea of complementing the existing product range at the same level of functionality. “Brick amps” are irrelevant in this context.

Why more power for the PCI MAX? The aerial may determine the range of the transmitted signal, however the Signal-to-Noise ratio determines how intelligible the received signal is. In an urban environment with a heavily congested FM spectrum, there is considerable interference from adjacent radio stations, thus a great amount of noise. In such an environment, 0.1W doesn’t “travel” far; it gets snowed under by the sidebands of radio stations transmitting at powers greater by some 6 orders of magnitude. Under these conditions, a signal of 2-3W can be received reasonably clear within the range determined by the aerial.

Therefore, more PCI MAX functionality and more power for it, please. =-)
J

Guest · Post by **Guest** » Sun Mar 31, 2002 2:59 am

I believe the power output of PCIMAX or ISAMAX is limited by the power supply inside
the computer. I am not certain, but suspect a 2 or 3 watt internal card exciter will not work in a quality manner. It might be possible to make PCIMAX up to 1 watt, like it's older brother ISAMAX.
Care to weigh in Marko ???

Post by **pcs** » Sun Mar 31, 2002 4:45 pm

Well, it is possible, indeed.

But as the power consumption increases
the noise from the PC increases as well.

We are taking it into consideration for
our future models.

BigJimW · Post by **BigJimW** » Wed Apr 03, 2002 1:38 am

On 2002-03-30 16:47, NikosE wrote:
In such an environment, 0.1W doesn’t “travel” far; it gets snowed under by the sidebands of radio stations transmitting at powers greater by some 6 orders of magnitude. Under these conditions, a signal of 2-3W can be received reasonably clear within the range determined by the aerial.

Hi,

You'd really be suprised how far 100 mW can go with the right conditions. I had a small problem Marko emailed me a fix on. My antenna is the Comet matched to the frequency I use, with 5 watt amp, RG 8 cable, etc. Without the amp, at 100 mW, overlooking the city, I can hear the station over 3/4 mile away. Thats a potential 35,000 listeners!

I agree though, if they put out even a 1 watt PCI card, then they'd have someting. This card is sweet.

<font size=-1>[ This Message was edited by: BigJimW on 2002-04-02 19:41 ]</font>

Guest · Post by **Guest** » Thu Jun 06, 2002 10:36 am

As far as i am concerned,the regulationf factor of pc based supply,is very poor if the current demand is fairly high

Grogster · Post by **Grogster** » Tue Jun 11, 2002 12:47 am

Hello!

Upping the output of the PCI MAX sounds like a great idea, but I would think that going for more then 1W or so, would make the cards uneconomical, and possibly result in not very many sales. Potential buyers are always gonna be attracted by the cheaper price, and unfortunately, RF watts are very expensive to buy - clean and stable ones, anyway. Sad, but true...

PCI MAX should have another jumper option to allow 1W or so.

This would be the most flexable, in my humble opinion, as this 1W figure is pretty much the standard input drive power required for most RF power-amps up to 30-40W or so.

Making a Tx co-exist in an already RF saturated enviroment, is not easy.
Noise aside, the PSU has plenty of grunt, and I would speculate, is suitable for any reasonbly thirsty RF amp up to around 10-15W, but weather this could really be done inside a PC is another matter entirely...

Just my 2 cents.

G.

Guest · Post by **Guest** » Tue Jun 11, 2002 8:19 pm

POINT BLANK----RF AMPS SHOULD NOT BE ENCLOSED IN A COMPUTER.TOO MANY PROBLEMS..200milliwatts IS ABOUT THE MAXIMIUM POWER THAT SHOULD BE available for amplification from the pci RF card.PERSONALLY I AM TOTALLY AGAINST INTEGRATEING A TX OF ANY APPRECIABLE RF POWER OUTPUT IN A PC.THOSE ARE MY VIEWS

Post by **pcs** » Wed Jun 12, 2002 9:26 pm

Well, receivers have been integrated
into PC from the very beginning.
You have ham receivers, FM radio receivers,
TV tuners, SAT tuners....

And receivers are far more sensitive
to PC's noise than transmitters, voltages
in a receiver are typically down to around
1uV (one millionth of a volt).

Think about it.

Grogster · Post by **Grogster** » Tue Jun 25, 2002 4:09 am

In reply to Anonymous: O.K. I can see your point here about RF amps in a PC case, but would like to know what it is that you are so against with respect to putting an RF amp inside a PC case of more then a watt or so...

I would speculate that a very strong RF field as produced by an RF amp, could cause some nasty responces the PC...

No idea if I am right - just a thought...

G.