The Panaxis ACC-100

Hi ArtisanRadio!

How is the ACC-100 better than the C Crane?

Is it transmitting distance?

Thanks and best wishes!

Bruce, MICRO1690/1700

Hi ArtisanRadio!

How is the ACC-100 better than the C Crane?

Is it transmitting distance?

Thanks and best wishes!

Bruce, MICRO1690/1700

There are several reasons why I felt the Panaxis was superior.

First and foremost, the C Crane is a stereo transmitter, while the Panaxis model that I had was mono (they had stereo versions, but they're greyed out on their web site). Now, while both will generate the same amount of RF for any given field strength, it takes a lot more energy to maintain that stereo separation and give you a listenable signal. And if you look at the specs of any FM receiver, you will find that while, in a good car radio as an example, it can receive a 2uv mono signal with quieting, it requires a 20uv stereo signal for the same quieting. Bottom line - you'll get clearer (and listenable) reception further with a mono FM signal than a stereo one.

To me, the C Crane was designed to listen to MP3's around the house, period. Yes, you can muck about with it to increase the field strength (the infamous screw under the decal mod), or add to the antenna length, but both those eliminate your FCC Part 15 certification. There was even discussion here about converting it to mono, but I personally wouldn't touch that unless it's for experimentation only.

The Panaxis sound quality was good - it's been slammed in varous forums but I found it somewhat better than the Crane's, at least listening to it from my car radio and with my source material (30's to 50's jazz & 50's to '60s doowop and pop). It was somewhat difficult to eliminate the hum from the AC power line, but I finally managed to get rid of most of it; the C Crane runs on batteries, so it does not have that particular problem (I can't remember if it also has an external power connection - if it does and you use that, it would likely have the same problem as well). Transmitters such as the Decade MS-100 sound waaaaaay better with no perceivable hum, but then they cost a lot more too.

There are several reasons why I felt the Panaxis was superior.

First and foremost, the C Crane is a stereo transmitter, while the Panaxis model that I had was mono (they had stereo versions, but they're greyed out on their web site). Now, while both will generate the same amount of RF for any given field strength, it takes a lot more energy to maintain that stereo separation and give you a listenable signal. And if you look at the specs of any FM receiver, you will find that while, in a good car radio as an example, it can receive a 2uv mono signal with quieting, it requires a 20uv stereo signal for the same quieting. Bottom line - you'll get clearer (and listenable) reception further with a mono FM signal than a stereo one.

To me, the C Crane was designed to listen to MP3's around the house, period. Yes, you can muck about with it to increase the field strength (the infamous screw under the decal mod), or add to the antenna length, but both those eliminate your FCC Part 15 certification. There was even discussion here about converting it to mono, but I personally wouldn't touch that unless it's for experimentation only.

The Panaxis sound quality was good - it's been slammed in varous forums but I found it somewhat better than the Crane's, at least listening to it from my car radio and with my source material (30's to 50's jazz & 50's to '60s doowop and pop). It was somewhat difficult to eliminate the hum from the AC power line, but I finally managed to get rid of most of it; the C Crane runs on batteries, so it does not have that particular problem (I can't remember if it also has an external power connection - if it does and you use that, it would likely have the same problem as well). Transmitters such as the Decade MS-100 sound waaaaaay better with no perceivable hum, but then they cost a lot more too.

I have always wanted an ACC-100, because
it is mono. But I don't have the cash right now.

In one phase of my Part 15 broadcasting, I
had a Ramsey FM-10. I was careful to keep
it in field strength compliance. I converted it
to mono operation. I also did some things to
it so it didn't drift after it was on for a short time.

It really helped my listeners to hear the signal. The
listeners were (and still are) good friends that
lived a few houses away from me. They listened on
their living room sound system. If I had been running
stereo, the signal would have been noisy. Their
receiver did not have a mono switch for FM.

This was about 7 or 8 years ago when I had the
time to actually put real programming on my
station. I hope to do it again someday.

Thanks again
Bruce, MICRO1690/1700

How can it be certified if it runs on 87.9?

I just bought a C Crane transmitter to give to my cousin so she could stream WNIU's online classical programs to FM radios in her home, which is not very big. Before taking the unit to her house, I decided to give it a quick test here. To my dismay, I could not even get a usable signal at 25 feet, and this was using a fairly sensitive portable FM radio (Grundig G8) on a reasonably clear frequency. Results were even worse with my GE Superadio III!

The signal from these things is so wimpy that they're essentially unusable even to transmit inside your own home! I tried attaching a clip lead to the unit's antenna, but that didn't make enough of an improvement to be worthwhile. Reception is actually fairly noisy at 10 feet! This is a a real disappointment! Maybe I will have to set up an SSTRAN at her house, but I don't know if she has any AM radios that are good enough for classical music listening.

Artisan Radio said "It was somewhat difficult to eliminate the hum from the AC power line, but I finally managed to get rid of most of it; the C Crane runs on batteries, so it does not have that particular problem (I can't remember if it also has an external power connection - if it does and you use that, it would likely have the same problem as well....There was even discussion here about converting it to mono, but I personally wouldn't touch that unless it's for experimentation only."
Geeze,if you really compared it to a CCrane,you would know it has an AC adapter and has absolutely no hum problems. Converting it to mono is super easy and causes no issue with its certification. I added a switch to a CCrane to switch between mono and stereo,works great!
However,I did not see that much difference in range so I use it in stereo,likely because most car radios switch to mono reception upon weak signal. I have 3 in service among several other brands...

Has anyone tried one of those power line clamp on ferrite cores? Might keep the RF out of the wall wart or vice versa.

I know it saved me a lot of grief with our City AM TIS operation. We had serious RFI where the RF was getting into one of our departments FAX lines. The transmitter is located on the 4th floor, the FAX on the first floor.

The RF was coming down the phone line from the 4th floor and into the FAX line. I bought a square, snap on core at Radio Shack. I wound several turns of the FAX phone wire on the core and the problem was gone.

How can it be certified if it runs on 87.9?

Dade City, your question is echoed by asking why the Scosche FMT4R is FCC Certified when it includes 87.5, 87.7 and 87.9 ?

I bought a whole stack of them and love them.

Modifying a certified transmitter voids the certification.

And I did indicate that I wasn't sure about the power supply to the C Crane. The Crane transmitter as delivered certified just wasn't all that useable, and I got rid of it rather quickly.

Transmitting in stereo and having a radio switch automatically to mono mode is somewhat different than transmitting in mono. I know from experimentation that the latter achieves far greater distance with a listenable signal. Perhaps its because a stereo signal degrades far faster than a mono one (as indicated in the specs for any radio - you need at least 10 times the signal strength to maintain a stereo signal with the same quieting as a mono one), and even if your receiver switches over to mono, it's still working with that degraded signal. Whatever the technical reason, if you want the greatest possible range on FM with a listenable signal, you should transmit in mono.

Not to argue with your experience or knowledge, however after a study of the composite signal for FM stereo, one should note that the maximum stereo pilot injection allowed for stereo audio signal by government regulation is 10 percent (approx. -20 dbvu). That is much more than 10db below the composite monaural audio signal, assuming no other audio sub-carriers are used. The stereo pilot, when used, reduces the mono audio signal (L+R) very slightly. The injected stereo signal does not affect the RF output of the transmitter at all. Therefore, technically, the RF signal is the same. The injected stereo signal (L-R) is only enough to turn on the stereo decoder and discriminator in the receiver. Left plus right (L+R) makes up the mono signal. So, when both signals are mixed together in the receiver, stereo imaging is produced in the left and right channels of the receiver.

When the injected stereo decoder pilot signal is not strong enough to turn on the stereo decoder, the receiver automatically becomes a (L+R) mono radio with exactly the same signal strength as when listening to the stereo signal. The loss of the stereo pilot gradually allows the composite audio signal to noise ratio to decrease to the point the receiver switches back to mono. The difference becomes the sensitivity of the stereo decoder in each receiver, not the amount of signal coming out of the FM transmitter.

Many years ago when FM was all mono, and we engineering types were learning how to broadcast stereo, we discovered that processing the "composite audio" (L-R, L+R, stereo pilot and sub-carriers) allowed the stereo signal to be heard farther away. Most Part 15 operators don't have the background or the money to afford composite audio processors for their mini stations. Plus composite processing is accomplished between the final audio dynamics processor and exciter/transmitter. Most part 15 stereo transmitters have internal stereo generators, not having the capability to process the composite audio. Way back when, we discovered that an unprocessed FM composite audio signal was not as easy to listen to by most stereo receivers. That is partly why the FCC established the "interference free" 1 milli-volt/60dbu contour for licensed stations. A Part 15 stereo FM transmitter produces that amount of signal no farther than 200-300 feet (max.) from the transmitter. Mono transmissions are heard, without the incumbent noise of the fading stereo pilot, further only because of the audio signal to noise advantage of the mono audio signal.

When the receiver doesn't have to decode the stereo pilot, double the audio signal is supplied to the receiver (L+R) making it easier to hear. The mono signal is not superior to stereo. It is fundamentally different. Like the difference between watermelon and cantaloupe. Both are melons; just different. How they are consumed makes the difference.

As a side note: most FM listeners expect to see the stereo pilot indicator come on in their receiver. When they don't see the light or LED come on, they think their radio is broken...or think there is something wrong with the station. It seems to draw attention to your station; and not necessarily in a good way. So, if you can still only use 10 milli-watts or less for Part 15 FM, why wouldn't you make it exactly what the listener demands in this day and age? That, of course, would be FM stereo. If not, remember; listeners have lots of choices of what to listen to anymore. If your station doesn't provide unique, compelling and memorable content, your station won't even be considered as a "possible", even if you stream online full time.

This is just my experience over 40 years and humble opinion.

I rebuilt a very old GE BT-1-A FM mono transmitter. While doing some extended "testing" of the transmitter I simply added a 19 kHz tone from a signal generator to the program audio. At just the right level the stereo indicator lamp on receivers would light up.

Maybe those of you that have mono transmitters can give listeners what they expect to see by adding the tone and lighting their stereo lamp. Most people don't really know what stereo is anyway.