I have teamed up with another broadcaster who knows Panaxis transmitters inside and out, in fact he was the one who provided Ernie the fixes for his FME FM transmitter back in the mid 80's. He also upgraded our AM transmitters by adding a trimmer cap for the crystal, and came up with a replacement for the MPF102 transistor that use to blow all the time. The transistors were also upgraded for improved output in our units, along with an improved power supply.
We are looking into recreating the Panaxis AM transmitter with the added modifications. If you ever owned a Panaxis, you know they were very loud, capable of 300% modulation. they also had a 50 ohm output and were not bothered by the presence of a FM transmitter like the Procaster and Sstran, regardless of power (We tested our Panaxis next to a 1000 watt FM transmitter), our Procaster will go into self oscillation in the presence of a 100mw FM. We are currently researching parts availability, and looking into adding PLL.
We think our recreated Panaxis will be far superior to the Ramsey AM25, and easier to build than the Sstran, along with a standard 50 ohm output which could used in carrier current.
With AM stations going dark in increasing numbers, and FM being crowded out, the market place needs more choices in AM transmitters that are a little easier on the budget. Not everyone can afford to shell out $800 for a certified transmitter.
We will keep you posted on what we come up with.
Steve
www.radiobrandy.com
a $700.00 transmitter gets screwed up by a $100.00 100mW FM.
Damn.
Now the question is why? and does the rangemaster suffer from this flaw?
REV BoB Says:
"a $700.00 transmitter gets screwed up by a $100.00 100mW FM.
Damn.
Now the question is why? and does the rangemaster suffer from this flaw?"
I says:
Huh? What the heck are you talking about?
The AM100 is what really got me started with 24/7 broadcasting! Building and operating that kit was entirely too much fun and I hope others will be able to enjoy that experience again.
I think one of the best features of the AM100 was that it was tough as nails. I probably hooked up every possible circuit backwards the first time and it just kept coming back for more.
If you're wondering what all the fuss is about, the original 1982 docs for the AM100 are located in our library, scanned as image files, here:
One thing I'd like to mention at this point as well is that all of the AM transmitters available to us now are, in my opinion, pretty remarkable. Just a few short years ago (well, 20 anyway, when I first became interested in AM part 15 broadcasting), there were very few options and none were affordable.
Now, thanks to the dedicated efforts of a few hardy vendors, the selection is really awesome. I feel quite strongly that there is no bad option these days, it's simply a matter of choosing the unit that's best for your needs.
What a great time for the hobby!
Robert, for some reason the Rangemaster is not effected by RFI from nearby FM broadcast in the 100 milliwatt range. After alerting Procaster to the problem, they were able to recreate it with a remote control used for model aircraft. I was told part 15 rules say you have to accept such interference.
Just plugging an XM radio into a Procaster, will send it into self osculation, I know it's not just the Procaster. Many Sstran users report the same problem, when it is used near an FM transmitter like the EDM.
One fix is to use an isolation transformer in the audio path, and ferrite beads on both the audio & power pack. sending a balanced signal over shielded cable helps a bit too.
Out of the box as shipped, plug your ears if you are near an FM transmitter when you turn it on!
The Panaxis AM transmitter for some reason is completely immune to RFI. Now the Panaxis FME 500 is a different story, it can't be operated around a 40 watt AM transmitter or it goes bonkers.
Steve
Radio Brandy
Here is what the stock Panaxis AM 100 looks like for those who havent seen one.
Radio Joe
After adding RF filtering on the audio, power and modulator, we believe we have fixed the interference issues that plagued the earlier units. It's not until you get some out in the field in different situations that these problems become known. We are always looking to improve our product and if you come across anything you think is not working as it should be, we would be glad to know about it.
"best features of the AM100 was that it was tough as nails."
You're right! You really had to work at it, to kill the AM100.
I had a pair with the 5 watt amp added, one was intended for standby. The standby saw very little service as the main ran 24/7 for five years and only needed the transistors changed out on the exciter a couple times from we driving them hard at +- 15 volts and the full 300% modulation the AM100 was capable of. Our transistors were all socketed, so changing them out was easy.
Each transmitter has its place, for an example: The Procaster is best for on the go legal broadcasting; like covering school football and softball games. The Procaster travels well and is easiest to tune up on the road and in tight spot like an attic. No need to drag the VOM around or a Inovonics 222 Audio Broadcast Limiter; just a screwdriver and crescent wrench for the U-Bolts will do.
The Rangemaster is the standard for commercial and government installations like schools etc. While it takes a bit more to tune up a Rangemaster, the results are worth it with greater range. Serviceability is also a plus with the IC's all socketed, if some reason you would need to change one out. It also makes an easier sale for government installations; because it is American made.
Sstran is great for those on a budget, and are comfortable with a soldering iron and building kits. Add Carl's antenna and it will cover a pretty good distance.
Back in March 1983 when I bought my first AM100, you had a choice of a LPB very expensive or the Panaxis AM100 under $100 bucks. The Graymark 505 AM transmitter had already disappeared from the marketplace long ago.
Who is not looking forward to the long anticipated AM Max3 from PCS? It will be great for carrier current operation for those confined to MDU's or restricted by CCR's.
The Myth that young people won't listen to AM is false! If you involve them in it, they will come!
Ernie really did change broadcasting for the better, How many of us got our feet wet on Ernie's transmitters? And bought his books? Imagine where we would be without Panaxis.
Long live Panaxis!
Steve
Radio Brandy
The Panaxis transmitters had their share of bugs that were only discovered in the field by us. Lucky for me, I had a genius when it came to Panaxis transmitters: AM & FM. Ernie would promptly incorporate the fixes into his plans and kits, and would also send out update kits. For the AM; the MPF102 would pop with the wrong Crystal or when you tried to tweak the Crystal with a trimmer cap. The FME FM transmitter clashed with the stereo generator, a tone could be herd in the background. A cap in the right place under the board and a few parts changed out corrected that problem.
Not all bugs are bad:
Some bugs can lead to great discoveries; without the bug in the Procaster, I would have never discovered that the Procaster is outstanding for horizontal attic installs. If was from that attic install, that I learned what a great transmitter the Procaster is for taking on the road. I figured if was that easy to mount and tune in a cramped attic, it would also be in the field.
Allot of sports and special events have been broadcast with the Procaster on site. People like the nostalgia of being able to bring a radio to the game where their kids are playing. You would be surprised how easy it is to find someone to do play by play on the radio. After the game, people come up to us taking interest in the transmitter asking questions about how and where they can get one.
When the economy turns around, don't be surprised if Procaster sales start to spike in the west. Who knows! The downturn might even be good for transmitter sales, as people have to find new ways to make money, and business needs lower cost ways to advertise.
I'm glad to hear the bug has been dealt with on the manufacturing end. It will make allot easier to sell the Procaster as the transmitter for non technical types & The Special Events transmitter of choice.
Perfect place to debug a transmitter:
If you ever see the documentary "Who Killed The Electric Car"available on DVD. They do a scene at the Willow Spring Raceway in Rosamond California; on some camera angles, you will see a radio tower in the background. That tower is 3000watt 93.5FM, and it had kept us from using the Procaster there for races, obviously a racetrack is a perfect place for the Procaster, thanks to that tower we were forced to solve the problem.
Turns out the Willow Spring Raceway is not only a great place to test out cars but transmitters too! Ground conductivity is great there too!
Steve
Radio Brandy
Since we are on the subject of Panaxis, are some of my Panaxis kits which I have that I built back in the early 80s . I called Ernie Wilison a few times when making these at the time. He always was willing to help. I learned a lot about transmitters from Mister Wilson. I bought a lot of his books also.
Power supply
FME 2000 2 Watt Transmitter
FMA 2000 2 Watt FM Amplifier
SG Stereo Generator
AM 5000 AM BC 5 Watt Amplifier
AM 100 100 MW BC Transmitter
.
Not only great photos Joe, but outstanding workmanship on your part. The cases that came with the Panaxis kits were less than ideal. The metal was real soft, which made it a little ruff when you pushed a button the whole front would bend.
Your photo of the AM100 reminded me of one part that may be hard to come by and that is the trimmer cap for tuning. I think Ernie was having a hard time finding them back then.
I just made contact with my engineer after 23 years, I'm sure he will be on this board soon. He thinks we can pull off the recreation of the AM100, the trimmer cap should not stand in our way.
Keep in mind the AM100 is not intended as a substitute for the Procaster or Rangemaster. It's intended for those who can't afford a Procaster or Rangemaster yet and don't mind a limited choice in frequencies in an a kit that is a little easier than the Sstran. The AM100 would make a nice building block for carrier current station.
Work in progress
Steve
Two oldies but goodies from Panaxis:
AMA 5000 Broadband Medium Wave Power Amplifier, .5 - 3 watts.
Meduium Frequency (A.M. Band) Transmitting Antennas; Theory, Construction, and Use.
check out the library. there is tons of technical info there from panaxis and the late pastor jr cunningham.
The FME Transmitter put out either 250 MW or 500 MW depending on how it was configured, I was wrong on posting it as a 2 Watt transmitter. The actual name of it was the FME 250 and FME 500, And thanks for the comments on the pictures, When I built these I made sure all resistors even lined up with the tolerance band all facing the same direction ! The cases are Bud Boxes, not the ones from Panaxis as pointed out. The trimmer cap on the AM transmitter you can get those yet, from a few sources, I think Electronic Goldmine or similar outlets will have them, I have seen them all over actually just have to look for them.
Radio Joe
Thanks for posting the AMA5000 and other Panaxis treasures online. Way back in the late 80's; Ernie had told me the iron cores were not available. If we could find them and the transistors are still available, I would make that amp a high priority for recreation too. If you have to do carrier current on the cheap, the AMA5000 is a must!
The phone companies must have made a small fortune from all of us seeking Ernie's help. My mother would blow a fuse when the phone bill arrived!
Steve
Radio Brandy