To start with I had the pair on a flat 19” rack which was rather exposed and didn’t have all parts integrated such as the PSU.  I had planned to box everything up but it wasn’t till I purchased a suitable box I got the chance to do it.  Here are a load of photos showing the final amp with the 2x G4BAO amps, the input and output hybrid combiners and the 24v 10A PSU.  The output is shown on the meter and peaks at about 80w.

The amplifiers:

The Hybrid Combiners:

Metalwork:

The Build:

In the Shack:

I always had it in mind to investigate this further.  Today I set about finding the BCD which selected 4m (70MHz) and found it with all BCD lines high (Band A=1, Band B=1, Band C=1, Band D=1, ) great!  On page 5 of the manual it shows the pin-outs, on BAND-DATA 1 or BAND-DATA 2 connect pins 4, 5, 6 & 7 together and then to 12v via a 1k resistor to get 70MHz. I noticed the amp would only allow LOW which I presume is to stop the PA’s overdriving into a non-optimized filter.  The fact that LOW is only fixed when on the 70MHz band lends me to believe the designers know this and allow it. Now to the interesting part.

With 25w in I get about 240w output, rather useful as the UK limit is 160w. Id was about 25amps though which at 33v is about 825w and means it’s about 30% efficient but none the less the amp does it.

However with 65w in I was getting a peak of 500w. 35% efficient.

I’ve not run this long term so it’s all at your own risk! I did run it for about 10 minutes to keep the dummy load cool, but for UK legal this should be a good option to get you to 160w with about 20w drive.

Update 2/1/12: G6UW ran their Quadra for 2.5 hours in the first 4m RSGB UKAC contest of the year without issue. On air their signal was clean and caused us no issue, they were an S9+50 signal with us being less than 10km away.

- APRS beacon built around a PICAXE-08M which periodically wakes up, beacons and shuts down.

- 3 x Azimuth rotator controllers. 2 for the CUWS (G6UW) and one for John G4BAO.

- Write up an AZ and EL rotator interface, basically my own version of an LVB tracker or ST-2.

- 30m QRSS CW beacon.

- RTTY modulator for my IC-756pro3 using a PICAXE-08X2 and XR2211, it already does inbuilt RX.

- Repair a mates FT-8800r.

I decided to build a new rotator controller to replace my Yaesu G400RC controller (but my design was made to work with virtually any rotator) to give me additional futures beyond the sole analogue position feedback of the G-400RC. I wanted the new design to be digital, have integrated PC control, hands off operation (pick your direction and then sit back) and have different modes of operation depending upon current operation style.  I had previously built a rotator PC interface but not a full blown rotator controller, however my original code covered most of what I wanted to do except the LCD hardware and user inputs.  This is a development in progress, since making it I’ve found I use the rotator controller differently to how I envisaged but I’ll cover that at the end.

I built the rotator controller around the PICAXE-20X2 chip which is far the best chip in Revolution Educations range and can be used in almost any design.  It supports almost all PICAXE BASIC commands and has 16 hardware inputs/outputs, it also has loads of registers and code space.  After using the PICAXE-20X2 chip on other projects I got my head round some of the advanced commands and my own limitations from when I done my original rotator PC interface on the PICAXE-28X1 chip.

My original premise was to split the rotator controller into modes, mainly to test how I would use each one and after using it I redesigned the code to make it an all in one but the modes were:

• Manual; standard control were the buttons change direction LEFT or RIGHT.

• Fast; this is like manual but the LEFT and RIGHT buttons move the desired heading faster than the physical rate of rotation and the antenna catches up.

• Preset; uses a dial (potentiometer) on the front panel to set a desired heading and the antennas track to that heading.

• PC Control, heading feedback to the PC works on all modes but setting the heading only works in Manual mode.  PC control also supports L for LEFT, R for RIGHT and S for STOP – this can be used also to interface to additional non PC [other BXF project] controllers.

The PC protocol is based on Yaesu GS-232 and I’ve included support for AZ only (GS-232A) or AZ+EL (GS-232B), in the GS-232B all EL commands are ignored or answered with 0 degrees.

After deciding what I wanted from the new code I set about looking for a suitable rotator controller, or box, to house it into which I found in Friedricshafen in the guise of a KR-400 control box for EUR 30.  It had a nice big south stop analogue meter in it but that didn’t worry me as I planned to use a 4×20 LCD (which I had bought off eBay).  I cheated slightly by using a Wulfgang K107 LCD interface board (tech doc .pdf) to drive the LCD, this was for 2 reasons;

1. It allows me to use serial to update the LCD instead of connecting all the parallel pins to the PIC so simplified the design, and
2. The K107 LCD interface supports large character mode (as seen in the pictures) so allows me to use the full height of the LCD better (easier).

The final code doesn’t have modes but instead allows any input to move the rotator, I did drop the FAST mode as it was redundant and I didn’t use it much.  The use now is you press LEFT or RIGHT to move in the desired direction, spin the preset to take you to the preset direction or press PARK* to take you to a pre-defined heading.  Pressing LEFT, RIGHT or PARK at any point cancels the current movement and start the new one, so if I set the preset to 200 degrees and pressed PARK (which say was set to 120 degrees) then the rotator would cancel heading to 200 degrees and head to 120 degrees.  The same is for the PC input, any PC input to goto a direction would override any current movement and head to the new heading set by the PC input. The PC can read the antenna direction at any time which does not effect the antenna movement.

* At present there is only one input used as a predefined heading, which I call PARK and have set to 120 degree, Europe from my QTH.  The PICAXE-20X2 has 5 additional spare inputs in this project so it’s more than capable of having extra switches attached to these inputs and assigning them to additional presets in the code.

Outside The Case

There was not much modification required to the KR-400 box.  I added an extra button on the front for PARK, originally for changing mode and on the back a 9-way D-type connector which I use for my rotator wiring as it’s much easier to disconnect, also all my other rotators use the same plug so they are all interchangeable. I also added a USB-B port on the back for PC interfacing, internally this goes to a USB<>Serial interface.  Inside is where the main changes are.

Inside The Case

The original circuit and meter in the box was of little use so the first thing I done was to remove both.  I left the transformer in along with the capacitor over the motor outputs which was also original, after that it was a new PCB with all the required circuitry and that was about it!

Calibration

The rotator controller needs calibrated.  This is done in a simple way by either powering on the rotator controller holding the PARK button or if the MINOffset or DirCorrect EEPROM values are 0 (no values stored in EEPROM would be the case after programming). When in calibration mode the user is presented with step by step text based commands on the LCD to follow for calibration.  You only need to do the calibration once after which MINOffset and DirCorrect values are stored on EEPROM and recalled on each power up.

The steps for calibration require the rotator to be moved fully LEFT (CCW) to 0 degrees (north) so the feedback pot in the bell housing reports its minimum value (MINOffset).

Pressing the PARK button saves this ADC value in EEPROM (MINOffset) which is then subtracted from ADC reads in the main code.

We then go RIGHT to 360 degrees (north) and save this ADC value (DirCorrect) which is used for the correction factor.

The ADC value is again saved in EEPROM when the PARK button is pressed.

Let me explain using my values.  On my rotator 0 degrees (north) returns an ADC value of 22, this ADC value is subtracted from all other ADC reads in the code, the reason is 22 is 0 degrees so an ADC value of 32 would be 10 degrees (it’s not quite that linear but you get the idea).  We then goto 360 degree (north) which in my case is ADC 953.  ADC 953 is actually not yet right as we need to subtract the MINOffset value for the correct ADC for 0 to 360, we then need to convert to a correction factor.

To get the most accurate heading I sample the ADC value in the code 64 times.  I use 64 [times] as this then fills a 16 bit register when sampling the ADC at 10 bits without the chance of it overflowing.  The maximum ADC value at 10 bits is 1024 so 1024 * 64 = 65636.

As my max ADC value is 953 (remember my minimum value of 22) I need to subtracted this off so the real ADC value is 953 – MINOffset or 931.  It’s the value of 931 which is loaded into the register 64 times meaning the register value is stored as 931 * 64 = 59584.  I then divide this by 360 to get the correction factor. 59584/360 = 165.5.  In PIC code we can only divide by full numbers so I take into account if the decimal is greater than 0.5 and if so I add a number to the correction factor to make it closer to the real value, if my result was 165.4 I would then use 165 but as it is 165.5 I instead use 166.

This means if I have an ADC value from the rotator of 546, I first subtract 22 (MINOffset) from it, leaving me with 524 which is sampled 64 times giving a register value of 33536 (in reality the ADC value of 546 could vary slightly on each of the 64 reads, one of the reason we average so many).  I then divide 33536 by 166 (DirCorrect) and I get a heading of 202 degrees.

Did you follow?

Schematic

Download the schematic (uses ExpressSCH)

Pictures

Code

Download the code

Old Design (PICAXE-28X1)

A long time back I decided I wanted PC control of my antennas, mainly for point and shoot, click on a heading in some PC software and start CQ’ing so that I wouldn’t have to think both about calling and antenna direction.  For this I ordered an LVB Tracker from AMSAT UK but before it arrived I thought I’d have a go at making one myself using PICAXE, it worked but it was crude!

I have a Yaesu G-400RC rotator which is the one with a round controller for the display and uses a comparator circuit to ‘match’ the heading of the controller display with that of the rotator itself, the problem is the comparator swings from –15v to +15v and is non-linear.  This meant interfacing to a PIC chip was possible (using an opamp) but as the voltage was non-linear it would not work so well.

My first attempt was using a PICAXE-28X1 chip which as good as a design it was I didn’t know PICAXE programming as much back then so didn’t fully utilise the chip, or code.  Instead of using the hardware serial (hserin) inputs, which allows serial reception in the background while the code executes, I used the normal ones and had to set a serial buffer timeout which would expire if no serial data was received, during this time all the code execution stopped.  Also due to my lack of familiarity of PICAXE code back then the code wasn’t really optimised, an example was lack of subroutines (Gosub) meaning there was lots of code repeated.  There was no calibration routine so working out the actual heading was left to the user to calculate and enter the correction values, for the ADC value, direct into the code. I’ve not reproduced the code here as it’s in my mind redundant and outdated.  But some of it was salvaged for this project.  What I did end up doing though was to take some of the ideas and features from this code and turned it into my LVB Extender design, an add-on for the LVB Tracker, which could send serial commands to the LVB Tracker giving added extra features and automation to rotator system without the need for a PC.

This can be used, along with gravity, to measure tilt, the angle vs down.  Comparing both X & Y axis outputs the resolution can be very small, smaller than is required.  Up until now the way I got the angle back was from one of the axis digital outputs by converting it to an analogue voltage by using an RC circuit which my elevation controller could work with, but not very well.  The main problem is the analogue voltage is not pure DC and I have in the past observed inaccurate readings and sometimes it just fails to work, but this maybe wiring also.  To cure this headache I set out to make the system as fully digital as possible so I decided to measure the digital pulses from both X and Y axis’s directly with the PICAXE-18M and then either convert that to a voltage with a DAC/digital pot or send it to the shack by serial and process it there by either re-designing the elevation controller to work with serial feedback or converting the serial to analogue there.

When I searched for info on this idea I came across a webpage by Frederic, F1OAT who has already used a PICAXE-08M with an MXD2125 – info about his circuit is here and at the bottom of this page here.  I also came access some code which uses a PICAXE-18M to control a Maxim DS1803 digital potover I2C, which I have some samples of, so in the end my solution uses that. I built a test circuit using a PICAXE-08M and with the help of Frederics code proved I could get it all to work.

The finished project uses a MXD2125, a PICAXE-18M, and a DS1803 and provides a fully ‘digital’ means of reporting the angle by converting it to a voltage.  I found at 0 degrees I get a voltage of ~0.2v and at 90 degrees ~4.3v out of the DS1803 which is about 0.045v per degree.  The digital pot has a resolution of 0.0195v per bit when fed from 5v.  No calibration is needed at the sensor end, only as much ‘swing’ as possible between 0 degrees and 90 degrees. As the output is linear the LVB Tracker is calibrated for 0 degree voltage and 90 degrees voltage and so knows what the angle is based on these to stored values, being digital it shouldn’t drift over time, something I think is happening with the RC circuit…

Code:

 ' 'The code relating to MXD2125 is 'taken from example code by F1OAT (frible@teaser.fr) Nov 2006. Symbol pin_x = 7 ; pin #5 <= MXD2125 X output Symbol pin_y = 0 ; pin #3 <= MXD2125 Y output ' CORDIC section variables definition Symbol x = w2 Symbol y = w3 Symbol ang = w4 Symbol ang_l = b8 Symbol ang_h = b9 Symbol dx = w5 Symbol dy = w6 Symbol i = b0 Symbol d = b1 Symbol neg = b2 Symbol tmp = b3 'The code relating to I2C or DS1803 is 'taken from example code by Peter H. Anderson, Elmore, VT, Aug, '04. ' Define IO Terminals Symbol SCL = 0 Symbol SDAIn = Pin1 Symbol SDAOut = 1 Symbol DevAdr = B0 Symbol PotNum = B1 Symbol PotSetting0 = B2 Symbol PotSetting1 = B3 ' Used in I2C Routines Symbol OByte = B4 Symbol IByte = B4 Symbol Ack = B5 Symbol N = B6 Symbol MSBit = B7 setfreq m8 ' increases the sample rate START: p_cordic: ; CORDIC section to guage the XY values (i.e. angle) x = 0 dx = 0 y = 0 dy = 0 ; Cumulate several pulses measurement to enhance accuracy for i=1 to 16 pulsin pin_x,1,ang ; high level pulse duration x = x + ang pulsin pin_x,0,ang ; low level pulse duration dx = dx + ang pulsin pin_y,1,ang ; high level pulse duration y = y + ang pulsin pin_y,0,ang ; low level pulse duration dy = dy + ang next i neg = 0 ; Put vector in proper 90° quadrant if x >= dx then qx1 x = dx - x ang = 2048 ; 180° neg = 1 - neg goto qx2 qx1: x = x - dx ang = 4096 ; 360° qx2: if y >= dy then qy1 y = dy - y neg = 1 - neg goto qy2 qy1: y = y - dy qy2: d = 1 ; CORDIC iterations for i=0 to 9 if y <= 32767 then pos y = 65535 - y neg = 1-neg pos: dx = x / d dy = y / d x = x + dy y = y - dx lookup i, (512,302,159,81,40,20,10,5,2,1), dx ; ATAN table for ang_premult=1024/90 if neg=1 then sub ang = ang + dx goto nextstep sub: ang = ang - dx nextstep: d = d*2 next i 'convert the angle to a value which can be used by the I2C routine. 'In this case it coverts it to numbers close to 0-255 for 0-90 degrees 'which makes it suitable to write this direct to the DS1803 ang = ang - 1965 ang = ang * 2 ang = ang / 10 Top: DevAdr = 0 'debug ang PotNum = 0 PotSetting0 = ang 'write angle to Pot0. 'PotSetting0 = 255 GoSub DS1803WritePot ' PotNum = 1 'Un-comment this code if you wish to use Pot1. 'PotSetting1 = 64 'Gosub DS1803WritePot 'Gosub DS1803ReadPots 'SerTxD (#PotSetting0, " ", #PotSetting1, 13, 10) 'debug PotSetting0 goto start DS1803WritePot: Branch PotNum, (WritePot0, WritePot1) WritePot0: Gosub I2CStart OByte = 2 * DevAdr + $50 Gosub I2COutByte OByte = $A9 GoSub I2COutByte OByte = PotSetting0 GoSub I2COutByte Gosub I2CStop Goto DS1803WritePotDone WritePot1: Gosub I2CStart OByte = 2 * DevAdr + $50 Gosub I2COutByte OByte = $AA GoSub I2COutByte OByte = PotSetting1 GoSub I2COutByte Gosub I2CStop Goto DS1803WritePotDone DS1803WritePotDone: Return DS1803ReadPots: Gosub I2CStart OByte = 2 * DevAdr + $51 Gosub I2COutByte Ack = 1 ' master is to ACK after receipt of byte Gosub I2CInByte PotSetting0 = IByte Ack = 0 ' no ACK as this is the last byte prior to the stop Gosub I2CInByte PotSetting1 = IByte Return I2CStart: High SDAOut High SCL Low SDAOut ' bring SDA low while SCL is high Low SCL Return I2CStop: High SCL High SDAOut ' bring SDA high while SCL is high Return I2COutByte: For N = 1 to 8 ' for eight bits MSBit = OByte / 128 ' beginning with the MSB If MSBit = 1 Then I2COutByte_1 ' most sig bit Low SDAOut GoTo I2COutByte_2 I2COutByte_1: High SDAOut I2COutByte_2: High SCL Low SCL OByte = OByte * 2 ' shift byte such that next bit is in most sig bit position Next High SDAOut ' null clock pulse to allow for slave to acknowledge High SCL Low SCL Low SDAOut Return I2CInByte: ' receives a byte, most sig byte first. ' result returned in I_BYTE High SDAOut For N=1 to 8 ' for eight bits High SCL IByte = IByte * 2 + SDAIn Low SCL Next Branch Ack, (NoAck, YesAck) NoAck: High SDAOut ' high Z on 9th clock pulse Goto I2CInByte1 YesAck: Low SDAOut ' logic zero on 9th clock pulse I2CInByte1: High SCL Low SCL Low SDAOut Return 

Images:

Revision:

240711 – Project posted to web.

The main features I wanted to add were the ability to input a wanted heading and then leave the rotator to goto that heading instead of having to hold any button down as the rotator can be slow and my attention span is short.  I wanted to have a button for ‘park’ to put the antenna in it’s ‘resting’ direction and an easy way to just rotate 45 degrees or 180 degrees (flip) at a time, I also added a button to toggle a relay which was used to switch the satellite antennas from RH to LH circular polarization and back again.

This shows how I interfaced the LVB extender (in yellow) with the LVB Tracker (in blue)…

In the end I used a PICAXE-28X1 chip as I needed a bit of program memory and lots of input pins.  The input buttons consist of UP, DOWN, CW & CCW plus LH/RH, Park, +45 degrees and +180 degrees.  The serial from both the LVB Tracker PIC and PICAXE-28X1 are TTL so I connected the serial to the LVB Tracker between the PIC and the MAX232 chip used for RS-232 level conversion.

Whenever UP, DOWN, CW, CCW, +45 degrees or +180 degrees button are pressed the first thing my LVB Extender has to do is read the current positions using the GS-232 “C2″ command which prompt the LVB Tracker to output both current azimuth and elevation positions which I read and store. From these positions the code works out what needs done with them.  If it is UP, DOWN, CW or CCW then it runs a loop to increment or decrement the original position for the duration of the button being pressed with increasing speed over time.  It writes the value back to the LVB Tracker on every loop.  If the +45 degree or +180 degree buttons are pressed the LVB Extender again reads the current positions using a “C2″ command and either adds 45 degrees or 180 degrees to the value and writes it back to the LVB Extender ensuring the write command has the originally read elevation value to this is not effected.  The Park button sends a stored position, from my old QTH in JO02ab the best heading for me was 127 degrees azimuth and 0 degrees elevation (best for monitoring 144.300 into Europe).  The Park heading is programmable only in the code, I made no provision to set it on the fly, main because I didn’t know how when I created this, I do now and will add it if requested.

The LH/RH button only toggles a relay to switch a voltage to the antennas.  If azimuth value reaches 360 degrees the code converts it to 0 degrees and if it reaches 0 degrees it converts to 360, both are able to be set if you like to go over the limits a little.  On elevation the counting is limited to between 0 and 90 degrees.

Code:

'Very few comments in this code, it's old and moldy... 'This code is used to extent the use of the LVB tracker http://www.g6lvb.com/Articles/LVBTracker/ 'an azimuth and elevation controller now available from AMSAT. There is lots of information 'available on the web about this unit. The extended features are to allow press and hold of the 'manual controls to the desired azimuth or elevation and adding presets and 180 degree swap. 'Definitions here: 'INPUTS > 76543210 'Usage Logic HW Dec 'Serial in from LVB In7 18 256 'Park In7 18 256 'North In6 17 64 '180 deg switch In5 16 32 'RH/LH Porolization In4 15 16 'CCW In3 14 8 'CW In2 13 4 'Down In1 12 2 'Up In0 11 1 'OUTPUTS 'Usage Logic HW 'CCW signal to LVB Out0 21 'CW signal to LVB Out1 22 'Down signal to LVB Out2 23 'Up signal to LVB Out3 24 'UNUSED Out4 25 'LHC LED Out5 26 'RH/LH control + RH LED Out6 27 'Serial out to LVB Out7 28 'Registers 'W11 = Azimuth Value (Decimal) 'W12 = Elevation Value (Decimal) 'W13 = Counter 'B9 = Delay Value 'B1>B4 = Azimuth 'B6>B9 = Elevation 'B10 = RESERVED 'B11 = 45 degree count (segment) 'B12 = Release Counter 'B13 = loop 'State constance - SYMBOLS are globals and makes changes easier in the future. SYMBOL park_azi = 0127 SYMBOL park_ele = 0000 SYMBOL north_azi = 0000 SYMBOL north_ele = 0000 SYMBOL delay = B11 SYMBOL segment = B12 SYMBOL amount = B13 SYMBOL Azu_val = W11 SYMBOL Ele_val = W12 SYMBOL fast = 40 'Delay after holding switched down. SYMBOL slow = 150 'Original delay SYMBOL Release = W13 'Define Inputs SYMBOL CCW_Val = %11110111 SYMBOL CW_Val = %11111011 SYMBOL Down_Val = %11111101 SYMBOL Up_Val = %11111110 SYMBOL Park_Val = %01111111 SYMBOL North_Val = %10111111 SYMBOL Sw_45_Val = %11011111 SYMBOL RHLH_Val = %11101111 'Do all power-up settings here: Set: high 6 'Sets the LHC LED on. low 1 low 2 low 3 low 4 delay = slow 'setfreq m8 Pause 2000 gosub lvb_read gosub lvb_write_azi Start: Release = 1000 Start_1: if Release = 0 then else dec Release endif If PINS = North_Val then goto north If PINS = Park_Val then goto park If PINS = RHLH_Val then goto switchpol If PINS <> %11111111 then goto PINCHECK 'Reset anything that has changed back to defualt states. low 1 low 2 low 3 low 4 delay = slow goto start_1 'Add this line here so it's the last state to check. This means when the up/down/left/right buttons are release 'the pins are set low again. PINCHECK: If Release = 0 then gosub lvb_read else endif If PINS = CW_Val then goto CW If PINS = CCW_Val then goto CCW If PINS = Up_Val then goto up If PINS = Down_Val then goto down If PINS = Sw_45_Val then goto switch45 goto start CCW: high 0 'debug Azu_val for amount = 0 to 20 If PINS=%11111111 then goto start if Azu_val =< 0 then Azu_val = 359 else endif Dec Azu_val gosub lvb_write_azi pause delay next delay = fast goto CCW CW: high 1 'debug Azu_val for amount = 0 to 20 If PINS=%11111111 then goto start if Azu_val => 360 then Azu_Val = 0 else endif Inc Azu_val gosub lvb_write_azi pause delay next delay = fast goto CW Down: high 2 for amount = 0 to 10 'debug Ele_val If PINS=%11111111 then goto start Dec Ele_val if Ele_val =< 0 then goto down if Ele_val > 200 then Ele_val = 0 else endif gosub lvb_write pause delay next delay = fast goto down Up: high 3 for amount = 0 to 10 'debug Ele_val If PINS=%11111111 then goto start Inc Ele_val if Ele_val => 90 then goto up gosub lvb_write pause delay next delay = fast goto up Switch45: gosub lvb_read if B0 = "-" then Azu_val = 360 - Azu_Val else endif Segment=Azu_val/45 Segment=Segment+1 Azu_val=Segment*45 If Azu_val > 360 then Azu_val=Azu_val-360 else endif gosub lvb_write_azi pause 300 for amount = 0 to 10 If PINS=%11111111 then goto start inc Segment Azu_val=Segment*45 If Azu_val => 360 then Azu_val=Azu_val-360 else endif gosub lvb_write_azi pause 400 Next amount goto start North: if B0 = "-" then Azu_val = 360 - Azu_Val else endif Azu_val = Azu_val + 180 if Azu_val => 360 then Azu_val = Azu_val - 360 else endif gosub lvb_write_azi pause 300 'if B0 = "-" then 'Azu_val = 360 - Azu_Val 'else 'endif 'Segment=Azu_val/180 'for amount = 0 to 1 ' If PINS=%11111111 then goto start ' pause delay ' inc Segment ' Azu_val=Segment*180 ' If Azu_val => 360 then ' Azu_val=Azu_val-360 ' else ' endif 'gosub lvb_write_azi 'Next amount goto start Park: Azu_val = park_azi Ele_val = park_ele gosub lvb_write goto start switchpol: toggle 5 'Swap the state of PIN 5 (RH/LH control + RH LED) toggle 6 'Swap the state of PIN 4 (LHC LED) pause 200 goto start lvb_write_azi: 'Convert Azimuth into hundreds, tens and units. B2=Azu_val/100 Azu_val=Azu_val//100 B3=Azu_val/10 Azu_val=Azu_val//10 B4=Azu_val 'debug b2 'debug b3 'debug b4 'debug b7 'debug b8 'debug b9 setfreq m8 serout 7,N9600_8,("W",#B2,#B3,#B4,13) setfreq m4 'Re-calculate current azimuth due to dividing it. Azu_val=b2*100 b3=b3*10 Azu_val=Azu_val+b3 Azu_val=Azu_val+b4 return lvb_write: 'Convert Azimuth into hundreds, tens and units. B2=Azu_val/100 Azu_val=Azu_val//100 B3=Azu_val/10 Azu_val=Azu_val//10 B4=Azu_val 'Convert elevation into hundreds, tens and units. B7=0 B8=Ele_val/10 Ele_val=Ele_val//10 B9=Ele_val 'debug b2 'debug b3 'debug b4 'debug b7 'debug b8 'debug b9 setfreq m8 serout 7,N9600_8,("W",#B2,#B3,#B4," ",#B7,#B8,#B9,13) setfreq m4 'Re-calculate current azimuth due to dividing it. Azu_val=b2*100 b3=b3*10 Azu_val=Azu_val+b3 Azu_val=Azu_val+b4 'Re-calculate current elevation due to dividing it. Ele_val=b7*100 b8=b8*10 Ele_val=Ele_val+b8 Ele_val=Ele_val+b9 return lvb_read: setfreq m8 serout 7,N9600_8,("C2",13) 'C2 requests current azimuth and eleavtion from LVB. serin 7,T9600_8,B0,B1,B2,B3,B4,B5,B6,B7,B8,B9,B10 'Store the response in to B0>B9 registers. 'serin 7,T9600_8,B0,B1,B2,B3,B4,B5 setfreq m4 ' for some reason all numbers appears to be $70 too large! subtract $70 from all numbers b2=b2-$30 b3=b3-$30 b3=b3*10 b4=b4-$30 B7=B7-$30 B8=B8-$30 B8=B8*10 B9=B9-$30 'debug b2 'debug b3 'debug b4 'debug b7 'debug b8 'debug b9 'calculate current azimuth into decimal Azu_val=B2 * 100 Azu_val=Azu_val + B3 Azu_val=Azu_val + B4 'calculate current elevation into decimal Ele_val=B7 * 100 Ele_val=Ele_val + B8 Ele_val=Ele_val + B9 return goto Start 

Revision:

240711 – Project posted to web.

I have been thinking of getting an amplifier for HF and 6m for a while but didn’t want to have 2 extra amplifiers in the shack, one for HF and one for 6m (50MHz).  There are a few options about for a combined HF + 6m amplifier and luckily a Yaesu VL-1000 Quadra (1KW HF and 500w on 6m) recently came available second hand at Martin Lynch and Sons so while standing out in the single spot in the garden at the Arran DX site where I could get decent and reliable Vodafone coverage I gave them a call, agreed a price and had it shipped, bullseye!

The Quadra needs to switch bands for bandpass switching which can be achieved by sniffing RF from the exciter or via Yeasu’s 4 bit Band Data interface which most Yaesu radios support.  However my exciter is an Icom IC-756pro3 and Icom do external band switching by varying a voltage on a single pin between 0v and 8v depending upon the band selected (note WARC bands are not individually identified), I could also use the CI-V frequency data (with CI-V Transceive set to ON):

L = Low / 0v, H = High / 5v

The Project

So what I need to do is build an interface which takes the Icom Band Voltage from the Icom IC-756pro3 ACC2 port and converts it to Yaesu 4 bit Band Data.  If I wanted to use just CI-V I could use a PICAXE-08M (8 PIN) which support 4 output pins, Yaesu Band A to D and one serial in PIN used for CI-V but the SERIN support for the 08M is limited.  I decided to go for a PICAXE-20X2 as it has a hardware serial pin, supports 19200 baud, the fastest the IC-756pro3 manages and gave me plenty of spare pins.  My final spec sheet was:

• Auto switching between CI-V and Icom analogue band data as source input.
• 4 pins outputting Yaesu Band Data to the Quadra VL-1000.
• 8 additional user configurable pins, i.e. selected pin go high on selected band to drive external equipment like coax relays.
• Support remote (on/off) switching of the Quadra VL-1000 by providing 13.8v to the Quadra when the IC-756pro3 is switched on.
• Have the PTT line integrated within the interface connections, it is not connected nor needed for the PIC.

NOTE:  I found the VL-1000 manual is close to useless with regards to the Pinout diagrams – it has a picture with pins numbered but has a list next to it in in letters A,B,C etc…  I also blew the 5A fuse inside my IC-756pro3 and damaged a track later on by not getting the 13.8v on the correct pin, i.e. following the manual so be warned.

The PICAXE code:

#PICAXE-20X2

#REM
v1.2 released 010911
Added funcionality for the 5B4AGN BPF on PinsC.

v1.1 released 230711
Improved CI-V string searching
Additional checks in Band Data routine to ensure we didn't get there by mistake

v1.0 released 130611
Initial release

#endrem

SYMBOL m160 = $01 '%00000001
SYMBOL  m80 = $02 '%00000010
SYMBOL  m60 = $03 '%00000011
SYMBOL  m40 = $03 '%00000011
SYMBOL  m30 = $04 '%00000100
SYMBOL  m20 = $05 '%00000101
SYMBOL  m17 = $06 '%00000110
SYMBOL  m15 = $07 '%00000111
SYMBOL  m12 = $08 '%00001000
SYMBOL  m10 = $09 '%00001001
SYMBOL   m6 = $0A '%00001010

'All these symbols are shifted one bit due to pin C.0 being blocked by HSEROUT.
SYMBOL m160c = $02 '%00000010
SYMBOL  m80c = $05 '%00000100
SYMBOL  m60c = $1E '%00000000
SYMBOL  m40c = $06 '%00000110
SYMBOL  m30c = $1E '%00000000
SYMBOL  m20c = $0A '%00001010
SYMBOL  m17c = $1E '%00000000
SYMBOL  m15c = $0E '%00001110
SYMBOL  m12c = $1E '%00000000
SYMBOL  m10c = $12 '%00010010
SYMBOL   m6c = $1E '%00000000

SYMBOL CIVinbaud  = B19200_64	'Change this to CI-V serial rate
SYMBOL CIVinPIN	= PinB.6
Symbol CIVorADC	= PinB.7
Symbol Band_ADC	= 6	'ADC6

SYMBOL Freq	  = W0 'B0, B1
SYMBOL CHSM1  = B2 'General register used in many places for calculations
SYMBOL CHSM2  = B3 'General register used in many places for calculations
SYMBOL MHZ	  = B4 'MHz register
SYMBOL KHZ	  = B5 'KHz register
SYMBOL MClear = B6 'Used to count the loop for clearing the serial memory
SYMBOL Search = B6 'Used to count where the CI-V identifier will be
SYMBOL Search2= B7 'Used to count where the CI-V checkbit will be
SYMBOL Lookfor= B8 'Used to substitute hSerPtr so we have a fixed upper limit when looping
SYMBOL Band	  = B9 'Used to save which band we are on, *reserved for future use

SETFREQ M64		'Run the code at 64MHz!!!

let DirsA = %00000000
let DirsB = %00001111
let DirsC = %00011110

HSERSETUP CIVinbaud,%001

Start:

IF CIVinPIN = 1 or CIVorADC = 0 then 'CI-V Code
IF hSerPtr  = 0 then goto start 'No seral data, no need to run the code.
Pause 1000 'wait a while to let the serial buffer to fill.

Lookfor = hSerPtr 'Transfer hSerPtr value to Lookfor as hSerPtr can still increase as we loop below

FOR Search = 0 to Lookfor 	'Loop to the value of Lookfor
 Search2 = Search + 6		'Search2 looks for the check bit $FD which is 6 places ahead of the CI-V identifier
 GET Search, CHSM1   'for each position in turn load the buffer into CHSM1
 GET Search2,CHSM2   'for each position in turn look 6 places ahead and load into CHSM2
 If CHSM1 = $05 and CHSM2 = $FD then goto LoadFreq 'Set frequency ($05) identifier and checkbit ($FD) found
 If CHSM1 = $03 and CHSM2 = $FD then goto LoadFreq 'Read operating frequency ($03) identifier and checkbit ($FD) found
 If CHSM1 = $00 and CHSM2 = $FD then goto LoadFreq 'Set frequency ($00) identifier and checkbit ($FD) found
Next 					'Go back to the start of the loop or finish

Goto ClearhSerPtr	'If we get here then we didn't find valid $00, $03 or $05 so clear the serial buffer

LoadFreq:			'We found valid serial data so process it and output the band data
CHSM1 = Search + 4		'Set where to look for MHZ value
CHSM2 = Search + 3		'Set where to look for KHZ value

GET CHSM1, MHZ		'Read the CHSM1 location into register MHZ, this is need formatting
GET CHSM2, KHZ		'Read the CHSM2 location into register KHZ, this is need formatting

BcdTOASCII MHZ,CHSM1,CHSM2	'Extract the MHZ serial value to individual registers
CHSM1 = CHSM1 - 48		'Format to decimal
CHSM2 = CHSM2 - 48
MHZ  = CHSM1 * 10 + CHSM2	'Add them back together

BCDTOASCII KHZ,CHSM1,CHSM2	'Extract the KHZ serial value to individual registers
KHZ = CHSM1 - 48			'Format to decimal (only need the first value in KHZ case)

Freq  = MHZ * 10 		'Combine the MHZ and KHZ value into one register
Freq  = Freq + KHZ
Select Case Freq			'Go find a match
	Case 10 to 29
		PinsB = m160	'Set PinsB to %00000001
		PinsC = m160c	'Set PinsC to the value required
		Band  = 160

	Case 30 to 49
		PinsB = m80 	'Set PinsB to %00000010
		PinsC = m80c	'Set PinsC to the value required
		Band  = 80

	Case 50 to 69
		PinsB = m60 	'Set PinsB to %00000011
		PinsC = m60c	'Set PinsC to the value required
		Band  = 60

	Case 70 to 99
		PinsB = m40 	'Set PinsB to %00000011
		PinsC = m40c	'Set PinsC to the value required
		Band  = 40

	Case 100 to 129
		PinsB = m30 	'Set PinsB to %00000100
		PinsC = m30c	'Set PinsC to the value required
		Band  = 30

	Case 130 to 169
		PinsB = m20	'Set PinsB to %00000101
		PinsC = m20c	'Set PinsC to the value required
		Band  = 20

	Case 170 to 199
		PinsB = m17 	'Set PinsB to %00000110
		PinsC = m17c	'Set PinsC to the value required
		Band  = 17

	Case 200 to 229
		PinsB = m15 	'Set PinsB to %00000111
		PinsC = m15c	'Set PinsC to the value required
		Band  = 15

	Case 230 to 269
		PinsB = m12	'Set PinsB to %00001000
		PinsC = m12c	'Set PinsC to the value required
		Band  = 12

	Case 270 to 479
		PinsB = m10	'Set PinsB to %00001001
		PinsC = m10c	'Set PinsC to the value required
		Band  = 10

	Case 480 to 540
		PinsB = m6	'Set PinsB to %00001010
		PinsC = m6c	'Set PinsC to the value required
		Band  = 6
Else				'No matcxh found, out of bounds
		PinsB = $FF	'Set PinsB to 0
		PinsC = $FF	'Set PinsC to 0
		Band  = 0
EndSelect
'debug
Goto ClearhSerPtr
'#REM
Else				'Band Voltage Code
Pause 100
IF hSerPtr  > 0 then goto start 'No seral data, no need to run the code.
ReadADC10 Band_ADC,Freq
Select Case Freq
	Case 860 to 983 '160m
		PinsB = m160	'Set PinsB to %00000001
		PinsC = m160c	'Set PinsC to the value required
		Band  = 160

	Case 700 to 799 '80m
		PinsB = m80 	'Set PinsB to %00000010
		PinsC = m80c	'Set PinsC to the value required
		Band  = 80

'	Case 575 to 676 '60m
'		PinsB = m60 	'Set PinsB to %00000011
'		PinsC = %00000100	'Set PinsC to the value required
'		Band  = 60

	Case 575 to 676
		PinsB = m40 	'Set PinsB to %00000011
		PinsC = m40c	'Set PinsC to the value required
		Band  = 40

	Case 010 to 147
		PinsB = m30 	'Set PinsB to %00000100
		PinsC = m30c	'Set PinsC to the value required
		Band  = 30

	Case 450 to 553
		PinsB = m20	'Set PinsB to %00000101
		PinsC = m20c	'Set PinsC to the value required
		Band  = 20

	Case 369 to 430
		PinsB = m17 	'Set PinsB to %00000110
		PinsC = m17c	'Set PinsC to the value required
		Band  = 17

	Case 369 to 430
		PinsB = m15 	'Set PinsB to %00000111
		PinsC = m15c	'Set PinsC to the value required
		Band  = 15

	Case 246 to 307
		PinsB = m12	'Set PinsB to %00001000
		PinsC = m12c	'Set PinsC to the value required
		Band  = 12

	Case 246 to 307
		PinsB = m10	'Set PinsB to %00001001
		PinsC = m10c	'Set PinsC to the value required
		Band  = 10

	Case 147 to 245
		PinsB = m6	'Set PinsB to %00001010
		PinsC = m6c	'Set PinsC to the value required
		Band  = 6

	Case 000 to 009	'ADC registered too low a voltage to be valid

Else				'No matcxh found, out of bounds
		PinsB = $FF	'Set PinsB to 0
		PinsC = 0	'Set PinsC to 0
		Band  = 0
 EndSelect

EndIf
'debug
'#endrem

ClearhSerPtr:		'Routine to clear the serial buffer
FOR MClear = 0 to hSerPtr
 PUT MClear , 0
NEXT

hSerPtr = 0		'Reset the HSERPTR pointer to 0

CHSM1   = 0
CHSM2   = 0
MClear  = 0
Lookfor = 0
Goto start

Download the code, schematics and PCB layout here.

The code is split into 2 sections based on whether the CI-V is connected.  If the CI-V is connected by default it is high which can be detected by the PIC which is what the line in the code equalling ‘IF CIVinPIN = 1 or CIVorADC = 0 then’ does.  If there is CI-V then the PICAXE runs the CI-V routine to decode the frequency and works out the MHZ and 100KHz, i.e 14.123MHz becomes decimal 141.  If there is no CI-V connected (the CI-V input to the PICAXE chip will be 0v) then the PICAXE uses a routine to look at the band data voltage using ADC to determine the band, first you need to make sure you don’t put more than 5v into the PIC, so you divide it with a couple of resistors R1/R2 so the voltage is 0.6 that of its original (i.e. 8v becomes 4.8v to the PIC). You then simply read the voltage as a function of ADC, 4.8v is 96% of 5v (we are using READADC10 which is 10bit value and the max ADC value is therefore 1024) so 4.8v = 96% of 1024 the [max] ADC value is 983. All we now do is for each band give a lower and upper limit for each ADC value (accounting for rig variance) and if the ADC value falls within a range then the appropriate band is chosen and BCD pins set accordingly.

If the band voltage is say 6.2v out the radio what band are we on? Reduced first by R1/R2 the voltage becomes 3.72v into the PIC, this has an ADC value (3.72/5v * 1024) of about 762 which rightly falls into the 80m band range. 80m has a lower ADC limit of 700 and an upper ADC limit of 799.

Remember the PIC code is split in 2, the top half is for CI-V decoding and the bottom half band voltage decoding.

When the radio is switched on 13.8v is taken from ACC2 on the IC-756pro3 which powers the PICAXE and also goes to the VL-1000 to switch it on, ensure the remote switch on the back of the VL-1000 is set to ON.

Updates:

230711 – Version 1.1 released:

• Improved CI-V string searching
• Additonal checks in Band Data routine to ensure we didn’t get there by mistake

Code now works fine with HRD controlling the radio over CI-V and all band switching works independent of whether the radio or HRD initiates a band switch.

170711 – I received an email from Jack Brindle, W6FB who commented “There is one change I would suggest in the output table, though. The BCD code 0×0 is not defined, but is used by some manufacturers. For example Elecraft uses it in the K3 for 60 meters. However, 0xF (all ones) _is_ defined as a no-band selector.”  So with that in mind I’ve changed the code so ‘no band selected’ is now all 1’s (0xF) – which turns out to be 70MHz, see my post about that.

150711- I received a comment from Barry GM3YEH who uses the Icom to Yaesu BCD Band Data Converter on his radio with N1MM contest logging software and a 5B4AGN  BPF and found the rig stays in sync with N1MM software but the BPF only changes to the correct band temporarily then drops into a ‘no band selected’ state after a second or two.  Barry suggested it might be down to N1MM polling the radio which the interface sees as 0v on the CI-V line which makes the code execute the Band Data Voltage code for which there is no band voltage data so it defaults to 0, ‘no band selected’.  On 230711 I reworked the code so it now has a much better CI-V ‘search’ string so it doesn’t get false values and also added an extra check in the Band Voltage code as there were times, as mentioned above, that the code would move there even if it was receiving CI-V data.

/END UPDATE:

And when up:

Mounting the SCAM12 I again took advice from Colin G4ERO and dug a hole about 100cm x 30cm x 30cm, bought a 2.5m long 178mm x 102mm x 19mm universal beam, modified it, (see below) put it in the hole and aligned it for vertical. I then concreted the bottom 50cm of it, let it set and filled and packed the rest with mud.

As the SCAM12 is able to rotate, there is a bearing in the bottom of the mast so it is not a good idea to mount it direct onto the ground.  So I welded a bracket on the bottom to hold the SCAM12 off the ground.  I then used threaded bar and some angle iron to hold it against the universal beam with some wood between both to tighten against.  Since these pictures were taken I’ve repainted the universal beam Hamerite ‘Highland Green’ which is more similar to the SCAM12 colour.

As the mast is pneumatic I got a small compressor for 30EUR at a Dutch Radio Rally which take 2 minutes 40 seconds to put the mast fully up.  I’ve fitted it with a remote control and pressure switch to it automatically switched off when at the correct pressure. The SCAM12 comes with a key to allow the air out and it takes a minute to come down.

There are guying points for 4 guy ropes on a slip ring but so far I have not guyed the mast at home and it’ has been up in quite strong winds, if I’m worried about the wind I only put a few sections up.  The sections can also be locked off if the SCAM12 is planned to be up for an extended period of time.