PNWQRP USB Radio Interface Project

PNWQRP USB Radio Interface Project Lyle Johnson, KK7P 11 July 2010 Salmoncon V

Background • Softrock Ensemble Receiver • Group SDR Exposure • Requires PC w/Soundcard • Soundcard Must Support Stereo Input • I and Q Signals for Subsequent Processing • I and Q? Think “Phasing SSB” • Most Laptops have Mono Input • Microphone • For Web Chats, Apparently

Ensemble Overview • Full HF Band Coverage 160m – 10m • Uses Si570 Local Oscillator • Wide Range • Very Clean (Low Phase Noise) • USB Based • Free Software • Rocky • Kit less than $60

Ensemble Soundcard Requirements • Low Noise • Sets Receiver Noise Floor • High Gain • Dealing with Microvolt Signals • Reasonable Dynamic Range • Could Definitely Use Preamp/Multi-Attenuator • Volunteers? • USB Interface • Not Required, but Convenient

TI USB Audio • PCM2900 Family • USB 1.1 (2.0 Compatible) • 48 kHz Sampling Rate • Limits Spectrum Display to +/- 24 kHz • Meets USB Audio Spec • Recognized by Windows XP and Later • No special drivers needed • Stereo In/Out • Might Want Tx Later 

USBRI Evolution • Soundcard Only • Cheap and Simple • USB Hub • Replace USB Port Consumed by Soundcard • Need a USB Port for Ensemble Control • Serial Port • Always Seem to Need (at least) One More • Radio Interface (C.A.T., Etc.)

Radio Interface • Radio Control (aka C.A.T.) • Icom CI-V • RS232 (Various brands) • Async not RS232 (some Yaesu, Kenwood ) • PTT • CW Keying • FSK

Radio Interface Standards • Standards? Dream on… • Think ”8-pin Foster Mic Connector” • Looked at RigExpert, MicroHam, Others • RE and US Interface • Same DB-25 Pinout • Readily Available Connectors • Must Be a Standard!!! • Adopted RE as Standard

Other Features • FSK • USB <-> Async Don’t Do 45.45 bps 5 Level • Didn’t Want to Make My Own • But Happy If You Contribute! • Pseudo FSK from FL Digi • DTR from MMTTY DLL • Jumper Selection • Ugh!

Other Features • CW • DTR • Shared with MMTTY DLL for FSK • K1EL Winkey 2.0 (June P&C) • Note: The following Winkey features not planned… • Paddle Input • Speed Pot • Message Buttons • … as this is a USB-powered computer interface. • All • RTS for PTT Function

Development • Project Proposed May 2010 P&C • Prototype Built by June 2010 P&C • Prototype Problems • USB Expansion Port Dead • Spare RS232 Port Dead • Prototype Successes • Audio • CAT (RS232 to K3) Using Commercial Cable

Prototype USBRI

Future Work 1 • Add Winkey 2.0 Support • Change Internal Dual RS232 to Quad? • Spare Serial • C.A.T. • Winkey (otherwise Jumper Select) • Dedicated DTR/RTS (now p/o C.A.T. port) • Possibly add PIC for Configuration • Eliminate Jumpers!

Future Work 2 • Design Update on Serial Port • Schematic and PCB Done • Finish Test/Debug of Existing Features • Isolation on Serial Port? • Isolation on C.A.T. Port? • New Prototype • Release for Ordering and Kitting

Possible USBRI

USB RI • Should be Under $100 Including Case • You Mark, Drill and Label Panels! • Any Volunteers to Arrange Punched/Screened? • RE Standard is ~$215 • MicroKeyer USBIII is ~$199 • US Interface is ~$369 • Larger Case Could Include Ensemble • EMI/RFI Issues? • Hope to Have 2nd Prototype Late August

Conclusion • Provides Consistent Way to Explore SDR • Useful Shack Accessory for Any Radio • Well, Almost Any Radio 

USB RI THANK YOU

PNWQRP USB Radio Interface Project