Advice on power supply & swr meter

SWR meter is what it is any will do the job better than none at all unless you want to spend a lot of money on the top of the range.
Power supply for that radio just need a small 3/5 amp but if you can afford it i would get a 30amp as if you get the radio bug you will want a better radio with ssb and more power but up to you

I started with a heavy-duty car battery which I would keep changed up until I got a 30A supply which although costly I saved something picking up a good one, second hand and it connects to several radios simultaneously so is a good shack solution if you find yourself with 2 or more sets on the go.

Alan

bought myself an Inac-FC25A and i have a little Maas SPS 33 II, under 75 euro each.

Does anyone have any experience of NEVADA PSW-30 or similar (seen a few makes that are very similar if not the same)?

Yes Bill, mine is an Alnico version of it and if it isn't made in the very same factory I will eat my hat as they say, the only visible difference on mine is it has 2 +/- inputs on the front not two.  I power several radios from it but only transmitting on one at a time and it does a grand job, especially as the HF set sucked the life out of the car battery quite quickly if the power was up at 100W.

As Alan noted, pretty much any combo/type of SWR meter will be good enough. I use the inbuilt one on my FT rigs, with an external reference old Pye Reflectometer (the proper name for an SWR reading instrument) that was intended for 35-500 Mhz but it's accurate enough for alignment of an antenna to within a PA safe SWR (2:1 or less). Remember that SWR just means (antenna resonance match aside) output RF energy measured vs reflected energy, so at PA safe levels (better than 2:1) your losing 50% or less energy that's coming back at the PA. So the lower you get, ratio wise, better efficiency and less back EMF hammering the rig's PA final.

But that doesn't mean your setup is efficient overall - between feeder losses and, unless you're using an optimal setup dipole or better antenna wise, some of your n Watts Tx is lost in the chain.

Talking of SWR, you can also tell something about efficiency by simply measuring how much current is drawn and a field EM measurement. A low field strength and very high unusual current draw can point to a nasty SWR state. And talking of current draw, if your radio lights (backlights or indicator lights) go dim, you're either drawing excess current that actually causing supply voltage to abnormally dip or you've otherwise got a PSU issue. Following on, if the reverse happens and you get a rapid offload ultra brightness happen, kill the bloody power like yesterday as the odds are the PSU regulation is kaput. Back before switch mode PSUs, if you didn't see that coming, you could end up with part barbecued rig or even a fire, white magic smoke of the very toxic kind was also probable. As anyone who did repairs on gear will tell you, 'magic' white smoke from fried or frying semiconductors is definitely not what you want to be breathing in.

As for power meters, unless you've got access to a properly serviced (calibrated) Bird or similar pro grade power measurement, don't trust what your average hobby radio power meter reads - it's an optimistic guide at best, but as I said earlier, measuring drawn current can tell you how hard the PA is working and most radios of any quality will have some spec data telling you the nominal (under a 50 ohm dummy load test) peak current for a selectable output selection.

I use a mix of solid power readings, em measurements and current draw to determine the validity of alleged RF power output.

Alan - Mirror Man wrote:

Yes Bill, mine is an Alnico version of it and if it isn't made in the very same factory I will eat my hat as they say, the only visible difference on mine is it has 2 +/- inputs on the front not two.  I power several radios from it but only transmitting on one at a time and it does a grand job, especially as the HF set sucked the life out of the car battery quite quickly if the power was up at 100W.

Thanks for that Alan. Was thinking of getting one as I like the size of it....just finding one at the right price now lol

I managed to pick mine up second hand at a significantly reduced rate, only weeks after I did another chap locally was giving the hobby up and offered me his 50 amp supply for around half the retail price so they do crop up.
I think he was quite keen on getting his ticket, another local chap took him along to one of the local clubs which seems to have put him right off I am sorry to say, I put it down to a bad experience with one individual but it clearly upset him enough to have a change of heart.

Hey everyone, I have a question. I setup a mobile radio as a base station in my home. I had an old Xbox 360 power supply kicking around so I tried it on my radio and it seems to work fine. But it only supplies 12.47v instead of the typical 13.8v (Which my on-board radio diagnostic calls a “Pass”) I’m curious if this could effect my radio performance. I’ve been told my modulation is low, could this be a cause?

James Mann wrote:

Hey everyone,  I have a question. I setup a mobile radio as a base station in my home. I had an old Xbox 360 power supply kicking around so I tried it on my radio and it seems to work fine.  But it only supplies 12.47v instead of the typical 13.8v (Which my on-board radio diagnostic calls a “Pass”)  I’m curious if this could effect my radio performance. I’ve been told my modulation is low, could this be a cause?

Hi Jim. I know nothing about Xbox 360 PSUs, but 12.47V should be fine if the PSU is capable of suppling enough current. Does it say on it what the amperage is?

Some switch mode PSUs designed to run computers can be used effectively to run rigs.. I use one, and mine runs at 12.1V. But some can't, e.g. if they don't kick out enough current, not smooth enough, or not filtered enough.

As said it's the Amp's that could be very low on that psu.
Better with a psu made for the job or a car battery.