GENESIS RADIO CALIBRATION PROCEDURES

Transcription

1 GENESIS RADIO CALIBRATION PROCEDURES covering all G59 models and GPA10 power amplifier

2 Si570 frequency adjustment

3 Si570 Frequency calibration This is a very straightforward and easy operation! 1- Set up your signal source (in this case a TS570D) in CW, at Mhz 2- Start your G59 and set your VFO A on same frequency - choose USB mode so you see your frequency divisions clearly in your panafall display. 3- In GSDR go to tab SET-UP>GENERAL>GENESIS CONFIG Look at the Genesis Si570 settings where you will find three frequency ranges. Calibration has to be performed on all three ranges. 4- Start the signal source and watch the signal appear on your G59. If your Si570 is off frequency (see screenshot 1), adjust the value in the box of the appropriate frequency range untill it is spot on (see screenshot 2) at Mhz. Each time you change that value you must press TEST to be valid. Si570 frequency off target correctly calibrated Si570 frequency

4 Si570 Frequency calibration using WWV as a signal source Of course you can all always use the WWV frequencies to calibrate the Si570 - I know Bruce (KF1Z) does - should you not have a second TX available. Screenshot below. Do you really want to have fun calibrating? Than choose Display mode: phase 2 and watch the circle slowing down the closer you get to the correct frequency!

5 RX image rejection

6 A- HARDWARE IMAGE REJECTION First start GSDR and select some frequency on 20 meter band. 20m band is recommended for optimum hardware image rejection results. Inject a good strong signal 15 to 25khz above or below the local oscillator (center ) frequency. See screenshot on page 4. Screenshots show 7 Mhz but procedure is identical. Signal should be at LEAST 70 to 80db or more above the RX noise floor. In GSDR go to Setup > General > Calibration WBIR box Press the (WBIR) STOP button. Adjust R23R on G59 board untill the IMAGE signal dips as low as you can get it. See screenshot on page 5. Your hardware IR is now set, leave R23R alone from now on. Then press the (WBIR) START button and proceed with the: B- SOFTWARE IMAGE REJECTION On to software... Now press RESET button in RX Image Reject Cal box. WAIT a few seconds (may take upto a minute even) after the image has completely disappeared into the noise. See screenshot on page 6. Then press SAVE. Important notice: Do the software calibration ( RESET/SAVE) on EVERY BAND, including the SWL bands if you use them. Repeat the software rejection procedure on each band to do the calibration properly. You can use a signal generator ( the built-in calibrator generator on MK2 and MK3 is there for this purpose). Or you can use a signal from a second transmitter ( proper dummy load or antenna of course).

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10 Hardware RX IR using Winrad by VK2DX Connect the G59 to sound card. It s easy - one stereo cable, one connector on PCB, one antenna jack. It is NOT confusing and you can not make a mistake! Here is the photo of PCB in phase 5: Next step: download and run Winrad. Now you may ask why Winrad and not GSDR? Simple reason: Winrad is very easy to setup, and you only need to select a couple parameters: LO frequency, sound card input and sampling rate. Winrad is RX only software and you will not be confused with settings which are not required at this stage. But most importantly, there is no WBIR (automatic software Image rejection) in Winrad so the only rejection you can do is the one in G59 hardware. To adjust IR, you need a signal source. Signal source could be any HF transmitter. Any carrier will do, ideally a couple of watts from your big radio. - Let s say that you have set LO in winrad to MHz. - Set your signal source TX to and tune You will see big spike on winrad 10 KHz above LO. There will be another signal 10 KHz below LO (14.190). This is the unwanted image, the signal you want to reject. The adjustment is HARDWARE thing, matter of turning the trimmerpot on G59 board either clockwise or counterclockwise until that spike on goes as away. See At this stage you will have few possible outcomes: - image is rejected nicely, 40dB or more below main signal. This means all OK, your G59 is all good and you are ready to move on, - image is rejected only few db, 10 or 20 db or so. This means that something is wrong with your G59 hardware. Troubleshoot G59. - there is absolutely no difference between signal and image, and no matter what, they are same amplitude: you have mono input on soundcard, wrongly wired cables or soundcard issue. Fix it, then go back to hardware adjustment. Screenshot of correctly rejected RX image (-40 db)

11 TX image rejection includes modification for G59 beta & MK2

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13 Hardware / Software TX IR using Winrad by ON4EZ This is done in a very similar way the RX IR is done BUT this time you are going to use Winrad as cheap spectrum analyser! This is how it is done: Connect the G59 to sound card. To adjust IR, you need a signal source. Now your G59 is the actual source. - Again,set LO in winrad to MHz. - Set your G59 VFOA to MHz and tune You will see your signal appear on Winrad 10 KHz above LO (in this case -3.3dB). There will be another signal 10 KHz below LO ( MHz). This is the unwanted image you want to reject. The adjustment we are doing now is HARDWARE, just turn the trimmerpot R9T on your G59 board either clockwise or counterclockwise until that spike on drops to the lowest possible value (G59 serial 017: value = db meaning a difference of more than - 60 db over the main signal). With that testrig the ideal setting of R9T came to 5K60 Ohms. (Further adjustment in GSDR yielded no extra rejection.) Further adjustment by band can be done in GSDR using the sliders and watch your signal image disappear even more (upto -15 db extra) if still possible. Screenshot of correctly rejected TX image in hardware (-61dB) your tools for additional software TX IR

14 I/Q balance, also called LO nulling or carrier suppression Adjustments: R9T is for TX image rejection. Trimmers R50T and R51T are for I/Q TX balance (carrier suppression). 1. Adjust image rejection with R9T. You should be able to achieve around 50dB of rejection on 40/30/20m band. The peak point is sharp and almost spot on 5K6. Don t worry about software adjustment at this stage. How much is a -50dB rejection? Well if you have no test equipment apart from a second receiver, then the G59 10mW signal transmitted into an external antenna should be S9 on your second receiver with a 1m piece of wire serving as a RX antenna. It could be more, but not significantly less. Let s say it is S9 (and you can make it to be S9 by adjusting the length of that piece of wire) then a -50dB signal at image frequency should be barely audible. If your main signal is S9 and the image is only S7, then something is wrong. Even worse- if there is no difference between the signal and image something is not right with the GSDR, cabling or sound card. In other words, you will know that you ve got it right when it is really well rejected. If you start with a signal set on the receiver which is well over S9 or well below S9, this may fool you. Of course, if your second receiver is a SDR receiver, then you will be able to see that difference much easier. Or even better on a spectrum analyzer. But if you already have one then you don t need my building tips anyway. 2. Now to I/Q balance: Measure the voltage on R41T and R43T (pins 2 and 3 of 4066). Let s say the voltage is 2.70 V. The next step is to adjust the voltage on R40T and R42T (pins 9 and 10) to match the above value. You do that with trimmers R51T and R50T. When you have all four voltages equal or as close to equal (without signal) then this is your starting point for carrier suppression. (carefull: adjusting one trimmer affects the settings from the other trimmer, so re-check all values after every adjustment! - ed.) Now fine tune those two trimmers for maximum carrier suppression. Note that all unwanted products are rejected even better than your -50dB image. measuring points adjustment point

15 - NOTE FROM EDITOR - (ON4EZ) : Here follows an extract from the operator s manual by Tasa (YU1LM) which I feel you should read as well in regards to I/Q balance and IR : - quote Choose 21MHz or some other HAM permitted band frequency the best is frequency range from 18-30MHz and find output signal with control receiver or SA(spectrum analyzer). All trimmer are in mid factory position. Adjust iteratively minimum this signal with trimmer potentiometers R50T and T51T carefully the sound card LINE OUT is not connected to G59 board yet. Connect sound card and adjust about 30% output pressing TUNE button in GSDR. In GSDR transmitting setup is chosen that transmitting audio IF is fixed an it is around 11 khz and it is possible adjust. G59 has possibility to work with audio frequencies in range from almost 0Hz to 24 khz but we are not recommending this option. Adjusting best performances with fixed audio IF 11 khz will stay in all frequency and it will not change that mean that is transmitter mode calibration extremely simple and very effective. It is always possible adjust in software image rejection over 60dB! Now find output signal take care that you not overload RX or SA because output level can be over +10dBm. Find image transmitted signal see picture with fundamental terms for SDR below and adjust image signal minimum with R9T. This adjustment will stay almost the same value at all HF frequencies. It is possible obtain few db more with carefully adjustment max 1or 2 turn left or right with balance I/Q trimmers R50T and R51T. You have to be aware situation that it is possible totally destroy previously adjustment with thisaction! All other transmitter adjust are possible only in GSDR software. - unquote 3. Now here is another problem: Too much drive from your sound card could totally ruin your signal! With too much drive (voltage set in GSDR very low, usually below 0.5V), products on the left and right from output frequency Fc+/-n x Faudio will rise significantly. This is manifested on a second receiver as multiple signals every KHz! Feed this dirty signal to a 100W amplifier and you ll sound like Chinese over the horizon radar! (poor calibration of max output power of your GPA10 may result in ruining your spectrum too!! See screenshots below. -ed.) How do you know you ve got the audio input level right? When all other products are below your image level! 4. Finally, adjust the TX image rejection in the GSDR software. You should be able to squeeze an additional 10 to 15 db. As you already know, I am not an expert in this field and the terms I use are non technical. For technical stuff see your nearest engineer. The aim of this write-up is to help new builders to get their output signal right without any measuring equipment apart from a Voltmeter and external receiver. I welcome your comments and further clarifications. Apologies for any unintentional errors. 73 Nick

16 GPA10 SOUNDCARD SETUP POWER LEVEL CALIBRATION courtesy of bruce greenleaf kf1z

17 G59/GPA10 Power output, and Power/SWR meter calibration. Bruce KF1Z Nov. 26, 2010 The purpose of this file is to detail how to set up G59 / GPA10 power output, and GSDR SWR/Power meter calibration. I ll assume that you have already set the parameters for your soundcard in GSDR : Setup > Audio > Soundcard. And also, that GPA10 is connected, and you have tested so far to see that there is RF output. So we will start here: Step 1. Setting the Soundcard Output voltage. In GSDR go to Setup > Audio > Soundcard. Look for the Output Voltage box, as shown below. Note: If you are using a Supported Card, you may not have this control. If that is the case, skip this step, and go on to Step 2.

18 Next, Unplug the cable coming FROM your soundcard, LINE-OUT, from G59. Attach the leads from you Voltmeter to the SHIELD and TIP of the LINE-OUT cable. Set your meter to read AC volts. ( 10 volt range ) Press the TEST button in the Output Voltage Box. Record the AC voltage measured. Press Abort in the pop-up. Then OK in the next pop-up. Type the voltage you measured into the white box next to the TEST button. Click on APPLY at the bottom of the dialog box. Now GSDR knows the maximum output voltage of your soundcard. Plug the LINE-IN cable back into G59. Step 2. Adjusting the Max Power Output. By now, you have realized that your G59/GPA10 does not output the rated power on every band. It may be low, or even very high. Now we will adjust the maximum power output on each band to the specified 10 watts. First off, make sure the GPA10 is connected to a 50ohm dummy load ( 20 watt minumum rating ), through an external wattmeter. ( can also use a oscilloscope, or spectrum analyzer for this step, instead of wattmeter.) As always, try to keep these measurements and adjustments short. We will be transmitting 10 watts continuously while making adjustments, and your heatsink will get VERY warm! A fan blowing on the GPA10 heatsink would be a good precaution. In GSDR go to Setup > PA Settings > Gain by Band You will see all the bands listed, with a settings box next to each. The numbers given will adjust the RF power output. A LOWER number, will RAISE the output. Default is 48.0 DO NOT click on CALIBRATE! But DO click RESET

19 Now that you re ready. Press TUNE on the main screen. Verify that the DRIVE slider is at 100 AFTER you press TUNE.

20 Look at your external power meter. Adjust the numbers in the white box next to the designator of the band you are on. up, or down with the little arrows. Adjust so your power meter reads 10 watts. Click APPLY. You now need to do this for EVERY band. Please remember to give GPA10 a chance to cool down from time to time! Step 3. Calibrate GPA10 Power/SWR measurement head. We start this step with GPA10 still connected to a dummy load, and wattmeter. Select the 20 meter band. Click TUNE in GSDR main screen. Adjust the DRIVE slider so you measure 1 watt RF output ( as exact as you can )

21 Following the test points shown in the picture above, make these adjustments as close as you can. Press TUNE, verify the power output is 1 watt. Adjust RT2X until TP-A measures 1.0vdc. Press TUNE to stop TX. Next : DISCONNECT the cable to the dummy load AT GPA10 BNC connector. ( you read right, in the next step you ll be transmitting into NO LOAD, so do this FAST!) Again press TUNE: With RT1X, set TP-B to 1.0vdc. Press tune to stop TX. Adjust RT3X so TP-1 measures between 2.0 and 2.5 vdc. This is the set-point that GPA10 protection will shut off the amplifier with high VSWR. At 2.0 volts at TP-1, the protection shuts off the amp at approx 5:1 swr. Good place to start, I would suggest no higher than 2.20 volts at TP-1, This should allow plenty of room to adjust an external antenna tuner, but still have adequate protection. Step 4. Adjusting FWD Power meter in GSDR. Ok, now we are ready to calibrate the power meter in GSDR. I suggest not using the New VFO Look but rather use the Edge Style or Original meter styles, As the are digital readout AND at the time of writing, the Analog meter does not agree with the others (Or, you CAN do this step using the new vfo look if you prefer it, and it will work fine, but keep in mind that if you switch between meter styles, the reading will be inaccurate ) For this step, again we have GPA10 connected to the dummy load. But now, we want the power output to be 10 watts ( DRIVE slider at 100 ). Go to Setup > PA Settings > ADC offset box.

22 ( These are my actual calibration settings, yours will be different) Settings here will work the same as when we set the output power in Step 2. Press TUNE, make sure the drive slider is at 100, and your external meter should read 10 watts. Change the number in the white box next to the band you are on, until the FWD power meter on GSDR main screen reads 10.0 watts. (See picture on next page) Click APPLY. Do this step for each band. NOTES: Above the power meter you see two drop-down menus. The left side is to select the RX meter function. The right side is TX meter function. Use the right side drop-down, you can select SWR Now you can just check your SWR right on the GSDR screen! After you get this all set up, you may just disconnect your external meter.

23 I hope this file will help you get set up. Hopefully not too many errors! 73, Bruce KF1Z

24 GSDR s-level calibration

25 S-level calibration procedure by Bruce Greenleaf - KF1Z. In order to facilitate readings on your display you should do the first step as follows: 1- GSDR SETUP - (IMPORTANT: AF PRE-AMP and ATT are OFF! -ed.) - Go to Setup > Display > Display Grid - Set MAX to Set MIN to Step: 6 - Align Auto - Check the boxes for vertical and horizontal grid ( this is how I run mine ALL the time... mainly these settings are pretty good, and gives a line that is at -73db, and 6db steps are pretty usefull in general) 2- Connect the signal source directly to the radio, turn it on. (your signal source needs to be a source such as a signal generator or a source known to inject a 50 microvolt signal = -73 db = S 9 -ed.) 3- Set the VFO to hz below the source, in USB (not critical... the signal needs to be inside the filter passband) 4- Go to Setup > Calibration In the Level Cal box... Enter your VFO frequency in the Frequency box enter the signal Level ( -73 db is S-9 with 50uV source) Click Start When it s done, you should see the tip of your carrier signal source right at -73db on the panadapter.

26 50 ohm dbm to microvolt Conversion Table dbm uv dbm uv dbm uv dbm uv

27 50 ohm dbm to microvolt Conversion Table dbm uv dbm uv dbm uv dbm uv