Amateur Radiosport from the Cheap Seats. By w. 4kaz, created on 2. Updated 2. 01. 7 0. Bob, N6. TV has a step by step guide on setting up a Red Pitaya posted to the skimmertalk list in which he documents version compatibility issues he encountered and outlines the steps he needed to follow to get his system functional. As of this date it seems wise to follow these instructions, or know that by diverging you may encounter issues of your own. There is also an illustrated how to guide now available from the folks at hamsci. Updated 2. 01. 6 1. Compatibility issueRecently discovered an interesting,  affordable,  and relatively new product called Red Pitaya, designed as an open source based piece of test equipment. As a piece of test equipment the Red Pitaya has basic oscilloscope,  spectrum analyzer, and signal generator apps available. The apps are designed to run as web applications with Red Pitaya board running a custom Linux and acting as a web server. Currently the apps are quite basic, but useful despite their simplicity. Possibly more interesting for hams are the SDR receiver and transceiver apps available from Pavel Demin. With the SDR apps, Pavel has taken this little Red Pitaya board into the areas of interest to many ham ops. The SDR receiver app has the ability to function with several currently available SDR programs. The ability to support feeding six channels into CW skimmer server is of particular interest. There are also transceiver apps which are being used by experimenters to build Red Pitaya based transceivers. Red Pitaya. The Red Pitaya itself is a board that runs a customized linux OStheir term is ecosystem off of an SD memory card. The board has two RF inputs and two RF outputs for use as the heart of a test system. V USB power supply input requires 2. A.   The board has a heat sink on the CPU but a small fan helps cooling. It can connect via ethernet to the network or via a wireless connection. The OS and apps are downloaded from the Red Pitaya website. SDR apps are available from both the Red Pitaya site and directly from Pavel Demins website. This little SDR kludge is a viable substitute for the Softrock skimmer system previously being run W4. KAZ. SDR Uses and v. Compatibility Issue. NLzbMcSHEtTgw3LOuScJrezl29v.jpg' alt='How To Install Virtual Oscillator' title='How To Install Virtual Oscillator' />A couple of issues turned out to be a mix of hardware and software problems. The largest problem was a software incompatibility issue between the latest OS v. SDR software.   This causes problems in the SDR with interference that looks like intermod artifacts. Too much time was spent here looking for hardware problems before stumbling across the documentation on the issue. The solution was simple. It simply required building an SD card with the previous OS version v. SDR app. A couple of the SDR apps available on Pavels site originally included an OS that did not allow a persistent password change. To avoid that security vulnerability, the original SD card here was built with v. OS.   As of October 2. NOT try to use v. OS with the SDR apps. V0. Artist interviews, downloadablestreaming audio, MIDI files, and howto articles. SDR.   Better to have several SD cards with different OS versions should you need a more recent OS for new apps as they are developed. Update 2. 01. 6 1. Gta San Andreas Pc Completo Download Games more. Per comment from Pave Demin, the SDR applications have been updated and should now work with v. Red Pitaya ecosystem. Not yet migrated to the updates here in the W4. KAZ SDR setup. After building the v. SDR app was good to go. Several different flavors of SDR are available from Pavel. The SDR app version that supports CW skimmer server also supports Power. SDR, which has a nice spectrum and waterfall display. There is not a tremendous amount of information available, as folks are just beginning to explore the possibilities. PA0. AER has an interesting post, with a few findings of his summarized in this table. PA0. AER published test data. Yeah, 1. 20db floor and 7. CW skimmer application. Keep in mind, the softrock system being replaced has about 4. Plus we get the bonus of using Red Pitaya as a minimal spectrum analyzer and oscilloscope. Maybe even a VNA app. SDR Station With Red Pitaya. First of all, one huge thumbs up to Pavel Demin for his open source work on the SDR apps. View and Download GE N60 instruction manual online. Network Stability and Synchrophasor Measurement System UR Series. N60 Controller pdf manual download. Radio Boulevard Western Historic Radio Museum. WHRM Radio Photo Gallery. COMMERCIAL MILITARY COMMUNICATIONS EQUIPMENT 1932 1942 1946 1969. Outstanding The time spent here going in circles chasing my non existent hardware issues was not completely wasted. The power supply  was cleaned up with better filtering. Very nice.  Using the AADE filter design program we also came up with a simple to build design for a high pass BCB filter. This filter optimizes the nulls at 6. This BCB filter exhibits low loss on 1. Ordinary C0. GNP0 capacitors are used in its construction, having had acceptable results with that type with the W3. LPL design band pass filters. The result was good with testing on the base station. The difficult part was finding good leaded C0. GNP0 capacitors in proper values to use for construction. Through hole components are becoming rare. NOTE As designed this filter is a short circuit at DC. W4. KAZ version of BCB filter. Built using NP0C0. G leaded capacitors, t 8. AADE predicted performance plot of the w. BCB filter from DC to 1. Mc. Note the nulls on 6. The plot projected by the AADE filter design program above is a best case prediction. WPTF, 5. 0kw at 6. WPTK, 1. 0kw at 8. They produced all sorts of intermod in the softrock system. The design is tailored to place the largest nulls where they might do the most work in the KAZshack. Getting the 3db cutoff at 1. Mc was just to try to keep the losses as low as possible on 1. To get an idea of its performance, I plugged it into the station and took S meter readings on the Kenwood TS 5. The BCB filter dropped WPTF at 6. S meter down to just another strong S9 signal. S meter comparisons on the TS 5. W4. KAZ BCB filter and built in attenuator. Skimming with Red Pitaya SDRWith the software issues corrected, let the CW skimming begin. Skimming tests seem to have spot signal levels from Red Pitaya SDR slightly better than those from the Softrock skimmer system. Full system stress test coming during 2. SS CW.  The Red Pitaya also seems to be very frequency stable, something that was a minor issue with the softrocks. When running Power. SDR, comparing Red Pitaya by ear shows it to be a bit less sensitive than the main station rig, a Kenwood ts 5. Does it work Random selected North American spot counts from days with W4. KAZ skimmer station under Red Pitaya. System Reconstruction Permanent New CW Skimmer. After a good shakedown voyage through Sweepstakes CW, it will be a good time to re arrange the test Red Pitaya SDR system into a more permanent and compact single system. One of the dead softrock CPUs will donate a nice clam shell computer case, and all of the components should fit easily. The plan is to wall mount the completed system near the shack cable entrance. The softrock system will be raided for its discrete components, the W3. LPL style band pass filters as well as the W7. IUV pre amps.  New splitters will be built for the new system to allow for antenna options to change in the future. Unexplored are some more experimenting to find a proper matching transformer and  Red Pitaya input jumper combinations for the best results. Some research into the transceiver experimenter comments indicate using a step up transformer is best. Some have also made mods to the front end that are supposed to boost the sensitivity by lowering the noise floor significantly, from 9 to 1.