Today I put the Coaxial Dynamics RF meter on the two FM transmitters. I used "slugs" in the meter specifically made for my purposes, as slugs for these frequencies and these low powers are not very common. Power read from antenna connection to ground on circuit boards inside the transmitters.
The Decade CM-10 gave a solid 2 mW out. Nothing else to test.
The Whole House 3.0 gave 2.2 mW on the USA setting.
On the "secret" Canadian setting the power jumped to a whopping 310 mW output!
Readings taken at frequency of 92.7, into a 50 ohm dummy load. Can't say for certain that 50 ohms is the actual design impedance output but it's pretty much the standard and either way the relative readings would be accurate.
Worth noting that I was testing the WH 3.0 with brand new batteries. When plugging in the power supply (not the one included, as that didn't work) there was a slight increase in output, maybe a meter needle worth. The USB supplies are 5 volts, the batteries make 4.5 so that little half a volt pumps it up just a little.
Now, remember this can have some bearing on the final field strength of course, but it's how the antenna uses the RF power to get it into space, and especially how other cables are connected and arranged. These readings were taken with nothing connected to the transmitters except power, and the WH 3.0 was also tested on just batteries with no power connected with similar results. Not that I was expecting any changes as this was with the meter hard wired to the outputs.
So, that's that.
I know have two FM transmitters for sale at half price. I believe the WH 3.0 is spoken for. The Decade CM-10 is up for grabs at half price, $100 + shipping.
TIB
OK so anywhere around 2.2 mW on USA and 310 mW canada. I think if we was to go for more power in FM that 500 mW would be what I'd go for into a rubber duck. 310 mW would probably cut it down to 1,000 feet of range around here which would probably be just a tad less than the SainSonic but not cause the bleed. But with 2 mW could cover more than 300 Ft to a good Radio. Its very interesting that I figured it was more than 100 mW at high. At least we know some power levels these transmitters are putting out. Wonder what the Signstek CZE-T200 would do on the 1mW setting to a rubber duck? Although its not certified would it by a gut bust if it was actually closer to legal at that setting? Something to ponder on.
Not to surprising there....both are similar in RF power.
On the wholehouse I don't think the high power setting was intended to be the "Canadian" setting as the high power setting is way to high for Canada. Although the transmitter power isn't of concern...only the radiated power.
310 mW is a huge jump from normal and with surface mount miniature transistors wonder how long it even would work at this power without eventually burning it out.
Wonder why this power boost isn't mentioned in the manual? because the transmitter could be sold to someone in a country where that power would be allowed and the field strength it could produce with a good antenna.
Interesting tests with interesting results....thanks for doing.
Mark
for doing the tests and posting what you found.
Neil
Yes Tim I am so glad you done these tests. Mark I am thinking the Signstek CZE-T200 is a 1mW,10mW,100mW,200mW transmitter. Remember I said that the Whole House FM Transmitter 3.0 looked a little like this one? Well is it not interesting that the Hi level is 310 mW? I don't know if they meant the high to be 400mW same as the Signstek or what? Reviews even said that the Signstek had better audio at lower power which does suggest that the high power mode does have an effect on the life span of the transmitter. It could also be why their range report at the 1mW level was close to the Whole House 3.0. Makes me wish I'd had bought that one as I could have controled the power and made it more complient and controled the bleed factor too. 300mW would be more than enough power if ever it came legal to use it at that power. The Sainsonic has even a bigger jump in power but I'd like to know what the low and high actually is for that transmitter and what it would do on a test as they claim certification.
If I had the money I'd had probably bought the Whole House 3 it did cross my mind to have bought it to compare it with my SainSonic but I just don't have money to spare. In the old days I would have taken the $60-70 and bought that transmitter. I'd have loved to compare it with my SainSonic to see the difference between 300mW and 500mW into a rubber duck.
...you're hot. I'll tell you this much, the Whole House 3.0 gets mighty warm after running it for even a half hour at "high" power. And the batteries start to die pretty quick. It stays nice and cool at normal output, and after running it for a full day the batteries still showed full. I expected a difference, but not quite that big of a difference, and certainly didn't expect it to run warm.
TIB
That is good info.
My SainSonic ran cool at the 500mW setting. Actually they intended this transmitter to run at that power all day and night. I've ran it from 12:00 Noon-4:AM and it was as cold as the first time I turned it on. I just wish I could have used power levels below the 500mW and in between. Like say 2mW, 10mW, 50mW,100mW, 200mW, and 500mW. At least I could really control the overkill for a hobby Radio system. It really is a poor design not to have a better variable than what they have used.
that was the case too.....it got warm, not hot, like too hot to touch but I use at regular power only and going by the range of the Decade use a 28" length of wire instead of the supplied antenna and this brings the range up to the "Canadian" strength approx. same as the CM-10. Wouldn't use the wire they supplied.
The 310 MW on high power I think without heat sinks would not be good for those tiny surface mounts and ya, batteries are no good at that power.
Still was a surprise that the CM-10 was over 1000uV/M by that much using as it came out of the box.
But the certifications give me peace of mind using.
I am worried about the power not working with the adaptor...could it be the micro USB jack on the transmitter that's bad?
If you can try with another 5 volt USB power supply and see if it works so I know it's not the transmitter jack then I'll buy with the price you told me $62 + $13 something for shipping. If you had apart for the power test, everything is back together and all works good?
In fact, maybe thelegacy would want it at this price so I don't mind if you offer it to him.
Mark
... But the certifications give me peace of mind ...
Kindly note that such Part 15 certification does not immunize the user of such equipment from regulatory action.
One well-known example of this is the NOUO issued by the FCC to the operator of "KENC."
True, Rich. Technically.
But as a practical matter, an operator who is using a Part 15 certified xmtr within its list of do's and don'ts... the NOUO is as far as it's going to get. The Commission will *not* fine a Part 15 operator who's clearly trying to play by the rules.
(This comment comes from a guy who has been subject to and examined by FCC inspectors since 1969. And has held six licenses for full-powered commercial AM/FM stations over those years. Which does not make my judgment infallible. But it does give me a record of history that I can share with my buddies here on this site.)
it's the power cube that plugs into the wall that's bad. I used another USB power adapter for my tests and it worked just fine. The one that came with it has no output. I tried to use it with other devices and there's just no juice coming out of it. The supplied cable and the connector on the transmitter work just fine.
I was initially faked out, as the certification docoumentation they provided to the FCC said the mini-usb port for power had been disabled and the unit only worked on batteries. But that's wrong, as this one works just fine on AC adapter or computer USB power as long as you're using an adapter that works.
Yes, it's perfectly back together and you'll never be able to tell that it was ever opened up.
Tim
Why are you here? What is your motivation?
To provide information useful to those wishing to comply with Part 15.
Why are you here? What is your motivation to provide information useful to comply with Part 15?