At the flying field with one of the old planes and a converted SS MP8K

The MicroStar 2000 is a state of the art, microcode driven, upgradeable, PIC controlled, Radio Control (RC) system for upgrading existing/older RC equipment. It is designed for use on the 6m Ham Band in the USA (FCC regulations) and supports full frequency synthesis and many additional intelligent features.

First, I would suggest going to Gordon Anderson's web site at to see what MicroStar 2000 is all about.
Here is a list of supported functions and features today:

I buy parts in bulk (lower cost) and provide Gordon's MS2K kits at cost because; I like the design, I want to introduce people to a high function (no kidding ........please check out the user's manuals on Gordon's site for details), LOW cost, PIC controlled RC radio, and I especially want to encourage building your own (you learn so much more). I also want to show that it does NOT cost many hundreds of dollars to convert your favorite older "made in the USA metal radio" (Single Stick or Dual Stick) Kraft, ACE, ProLine, Heathkit, EK Logictrol, etc to a modern RC unit. In fact, you can perform the MS2K Conversion for around $70 for the MS2K Encoder Kit plus around $40 for a fully synthesized 6m MS2K RF Deck Kit.

These units are intended for the 6m Ham Band so you will require a (no code) Technician License or higher in the USA. This is NOT difficult to do and I would suggest contacting a local ham radio club in your area. They will be more than happy to help you and they generally offer several classes and exams throughout the year. The MS2K 6m Ham Band only constraint is the result of USA FCC regulations, your country requirements may be different.

There is group of people on "MP8K" at Yahoogroups, very familiar with the MP8K and MS2K and they are more than happy to help you out (including myself). I can provide a detailed bill of material of what is provided if you request it. You will be surprised at the low cost but there is NO compromise on part quality. I get there through quantity buys and new surplus parts and there is "$0" personal profit. I'm doing this for the reasons stated above. Future kit runs will vary some in price/content because it depends on what is available when I kit another batch up.

If you feel you may have problems assembling the MS2K Encoder kit or MS2K RF Deck kit, one of the group members offers a kit assembly service for a very reasonable price. That's fellow RC'er, Danny Miller, [email protected] He is experienced and does excellent work.


The Encoder

Shows an assembled (by Danny Miller) MS2K Encoder V5.x. The board measures only 3.9" x 1.8" which will fit nearly any radio. The 2x16 LCD (with backlight) with it's IDC cable, and the other connectors are supplied in the kit but are not shown. The picture shows right angle headers, I provide straight headers in my kits.

MS2K V5.x ENCODER KIT ...all the parts to be mounted on the board

The "will it fit my old RC radio enclosure ?" measurements are:

I always try to go for the "lowest cost which meets the requirements" and can price it at $70 which includes: 12bit ADC microcontroller soldered and programmed, USB Interface chip soldered in place, 2x16 backlit LCD display with cable and IDC connector and plastic bezel, 6 pin and 8 pin DIN receptacles, 9 pin Serial connector, and mating header connectors.

Please add $4.00 for shipping in the USA.

Options: plus $5 extra if you want my USB to USB cable for connecting between your radio and your computer (or maybe you already have one you want to use). Note: I used to offer a microcontroller with 10bit ADC for $10 less but ran out of those parts and most people wanted the 12bit ADC anyway, so I only offer the 12bit ADC now.


The RF Deck

Shows all the parts which come with a MS2K RF Deck Kit (front and back of an assembled board). The mounting nuts are not included in the kit, but you can get them off any PC card "D" shell connector.

MS2K SYNTHESIZED RF DECK KIT ...all the parts to be mounted on the board for use with the MS2K Encoder. This kit does NOT support standalone use (without the above MS2K Encoder)

TOTAL price for the kit is $40 plus $2.50 for shipping in the USA.


Shows an assembled MS2K PulseStar Receiver Ver 3.0. The board measures only 2.1" x 1.5" and comes with a plastic case.

Typical PPM receivers use a simple shift register as a decoder. This type of design is very susceptible to interference and glitching. I’m sure you have experienced this problem especially when you run an electric drill next to your radio and see the servos jitter about. The PulseStar uses a microcontroller to record the data from the detector and inspect the pulse train. Several checks are performed to insure the data frame is valid. Only valid data frames are decoded and sent to the servos. If a bad frame is detected, the PulseStar will throw it away and use the last valid frame. If no valid frames are detected for a user-defined amount of time, the PulseStar will send the servos to there fail safe position.


The PulseStar’s Computer Interface allows you to configure the receiver using your PC. The configuration information is saved in non-volatile memory. The PulseStar records status parameters during a flight. These parameters include the number of invalid frames, the number of times fail safe was entered, average signal strength, etc. These parameters can be downloaded to a PC for analysis after each flight. You can even record the signal strength as a function of time to allow you to evaluate your flying site.

The 20 pin option connector is included to allow for future optional accessories as well as providing a easy way to set the operating channel. This option connector is a unique feature of the PulseStar and will allow development of the following accessories:

Option connector allows:


Shows an assembled MS2K Computer Interface as discussed in the above MS2K PulseStar Receiver section.

OK now for a little fun. Do you know what the antenna radiation pattern looks like for a RC whip antenna generally pointed in the area of "towards the aircraft" ?

This is my take on 1/4 wave RC whip antennas and is based on the program EZNEC by Roy Lewallen (the simple version is available as a free download). There may be more/better data available but this tells the story. The data is about 6m RC units but the same info applies to 72Mhz units.

Basically antenna "matching" .....changing antenna length, loading coils, etc effects the PA efficiency and controls the power being transferred to and being radiated by the antenna. The EZNEC program tells you what the radiated pattern looks like after that for various shapes of antennas, ground characteristics, etc and shows both azimuth and elevation plots.

I assumed a 1/4 wave Tx whip antenna on a transmitter approx 3-4ft off the ground with the antenna held at a 45 degree angle (in the X-Z plane on the plot). I don't know how to simulate the effect of a person holding the Tx and at the end of the antenna, but suffice it to say the signal pattern behind you is distorted .......(and not considered).

A good antenna pattern comparison would be to picture the top hemisphere of a balloon. Assume your transmitter location is at the center of the balloon. Now take your finger at 45 degrees, point at the center, and push into the balloon. What you now have is a rough idea of what the pattern looks like. In other words, the lowest signal will be in line with the antenna, increases in a conical shape until you get to the strongest signal which is perpendicular to the antenna.

A "vertical slice" of the signal profile which includes the antenna, viewed parallel to the ground and the antenna is at 45 degrees

A "horizontal slice" of the signal profile, viewed from the top, elevated 35 degrees off the ground from your position

So what does this mean. To add some rough numbers: In line with the antenna was a reduction of 10dBi which means the signal power off the end is about 1/8 of what it is off the sides .....not much. A cone +/- 30 degrees from the antenna axis has a reduction of 6dBi which means a signal power of about 1/4 of what it is off the sides. A cone +/- 45 degrees from the antenna axis has a reduction of 3dBi which means a signal power of about 1/2 of what it is off the sides. There is a VERY substantial reduction in signal strength all the way around the transmitter location and up about 10-15 degrees from the ground.

And just to complete the story ....this is what happens when you drop/raise the antenna relative to the ground. The previous data was with the antenna at 45 degrees from the ground .....these are for the antenna pointed downward (tip 6" to 12" from the ground), at 0 degrees (held horizontally), at 30 degrees, at 60 degrees, and at 90 degrees (held vertically).

A "vertical slice" of the signal profile which includes the antenna, viewed parallel to the ground. The antenna is pointed downward to where the tip is 6" to 12" from the ground. This is a typical "sloper" antenna pattern. Looks pretty darn good !

A "vertical slice" of the signal profile which includes the antenna, viewed parallel to the ground. The antenna is at 0 degrees (held horizontal).

A "vertical slice" of the signal profile which includes the antenna, viewed parallel to the ground. The antenna is at 30 degrees.

A "vertical slice" of the signal profile which includes the antenna, viewed parallel to the ground. The antenna is at 60 degrees.

A "vertical slice" of the signal profile which includes the antenna, viewed parallel to the ground. The antenna is at 90 degrees (vertical).

Modern receivers requires a very small signal to function properly so you will probably not see any effect at close range.

However, the above indicates:

  • 1) Don't fly planes close to the ground (within 10-15 degrees from the ground) a long way off.
  • 2) Don't point the antenna directly at the plane because that is the lowest level of signal when flying a long way off.
  • 3) If you loose communications turn the transmitter antenna perpendicular to the plane.
  • 4) Looks like a good antenna position is as a "sloper" pointed in the general direction of the plane but with the antenna tip DOWN, 6" to 12" from the ground.

OK now for a little more fun. Ever wonder what signals are lurking at the field ?

Here is one way to find out. Find a Bearcat BC60XLT-1 (I used this model because I had one .....probably several others will work also). The 10+ year old "BC60XLT" will not work. The BC60XLT-1 are very popular, very common, and sell for around $40 to $50 (sometimes less) on ebay. This is a 30 channel scanner which works pretty well, uses the UC1782 or UC2345 module, and is set up for 29Mhz to 54Mhz, 137Mhz to 174Mhz, and 406Mhz to 512Mhz. Doesn't look too useful's popular, cheap, but wrong frequencies and not enough channels ?? aaaaaaah !

First, make sure it works correctly because you don't want to chase problems you didn't create. Then take the 4 screws out of the back (two are in the battery compartment) and pull the rear cover off. Yes, it does come off.

Here is an example of the rework required for a UC1782 processor

Remove the top board which is has one connector to the lower board does come apart. Remove the 4 screws holding the shield over the processor. There should be 2 solder pads below pins 1 and 2 of the processor (lower left corner when viewed from the back, count counterclockwise. One pad is wired to pin 2 of the processor. Add a wire jumper across the pads and you now have an 80 channel scanner and one problem is resolved.

These scanners are designed as a USA version with 29Mhz to 54Mhz --OR-- a European version which scans 66Mhz to 88Mhz. You really don't need that battery charger switch in the battery compartment since these scanners run a long time on regular batteries. Look at the first board you removed and you will see a large resistor which has a trace going to the switch, cut the trace. Solder a small wire to the portion of the trace which still goes to the switch and solder the other end to pin 1 of the processor on the other board. Be careful to not break the pin off the processor or solder bridge to pin 2. That switch now serves to ground pin 1 (please re-check your wiring). Grounded is the European version, Ungrounded is the US Version.

The purpose of the switch, which originally shorted out the resistor in the "NiCad" position, was to provide a ~1.5 volt drop to the scanner if your are using 4 alkaline batteries. Four alkaline batteries = 6V, four NiCad batteries = 4.8V, and the scanner is designed for "4.8V". The resistor is always in the circuit after the mod so 4 nicad batteries should not be used (voltage now too low ....4.8V - 1.5V = 3.3V).

Put the thing back together again (with no parts left over).

Now what you have is a scanner you can set for the ten 50Mhz frequencies, AND the fifty 72Mhz frequencies (with channel 11-60 readout), AND the eight 53Mhz frequencies, AND get weather reports, AND you have 12 more frequencies to program for whatever. Pretty cool. The scanner, when set for "USA version", will allow entry of 50/53Mhz frequencies and give an "error" for 72Mhz frequencies and when set for "European version" will allow entry of 72Mhz frequencies and give an "error" for 50/53Mhz frequencies. However, when all the frequencies are loaded it will scan both 50/53Mhz and 72Mhz just fine and stop when it encounters a signal in either RC band. Since the scanner is basically a "receiver" it helps if you have a longer, 41" or so, antenna. A long telescoping antenna with a BNC connector works great.

Got another scanner and it's a later version which has the UC2345 processor, smaller components $%#@!! (a real test for my old Weller WCTP and head magnifier), and a new PC board layout. The pins to be modified remain the same 1 and pin 2. Same type rework as above. Picture below. On this one it's actually easier to "float" pin 1 off the board and bend it --carefully-- to the side to prevent solder bridging. Functions just as well as the other unit.

Here is an example of the rework required for a UC2345 processor

Here is what you can use the spare 12 channels for .....a very rough spectrum analyzer.

The filters in this scanner are set so you can not choose a granularity less than 5Khz. Example; if you have a transmitter on Ch 34 (72.470Mhz) set the following 72.450, 72.455, 72.460, 72.465, 72.470, 72.475, 72.480, 72.485, 72.490 that's a range of 40Khz. Turn the squelch off and listen to your transmitter with the Tx antenna down. Using the small scanner antenna (a longer one would be better), this is what I heard on one of my NB transmitters:

  • 72.450 background noise
  • 72.455 background noise
  • 72.460 signal but distorted
  • 72.465 good signal
  • 72.470 slightly better signal
  • 72.475 good signal
  • 72.480 signal but distorted
  • 72.485 background noise
  • 72.490 background noise

If the center was shifted 5Khz (or more) it would indicate a bad, off frequency, crystal.

You can also check for "off frequency" interference by setting "chain search" on the scanner ......say for Chain 1 from 72.00Mhz to 73.00Mhz, Chain 2 from 50.78Mhz to 51.00Mhz, and Chain 3 from 53.00Mhz to 53.90Mhz. This will search those (selectable, two or all three active) frequency ranges in 5Khz increments looking for signals.