Iceni 70cm transverter By G4DDK EME2018 Contents Introduction to - PowerPoint PPT Presentation

Iceni 70cm transverter By G4DDK EME2018

Contents • Introduction to the Iceni • Design of the transverter • Device update • Analysis • receiver, • Transmitter • Local oscillator • Frequency locking • Summary

Iceni -A 70cm transverter design for the home constructor

• An ancient Celtic tribe who inhabited the east of England Iceni (I-see-nee) 2000 years ago. • Their queen, Boudica, famously drove the Romans out of Colchester and London, before suing for peace (was this the first attempt at Brexit?)

Iceni design The schematic block diagram of the Iceni will be familiar as that of a conventional single conversion Up/down converter. Control/ interface Transmit 28MHz Input Amplifier attenuator 432MHz Mixer Filter 28MHz IF Post mixer Amplifier & BPF RF Amplifier 432MHz 101MHz 101MHz Xtal LO Multiplier oscillator

Device update Due to Broadcom acquisition of Avago, certain devices are no longer available However, thanks to MiniCircuit Inc. • PGA105+ replaces the MGA30689 Last year, after input from SM5BSZ, the • PSA4-5043 replaces the SPF5043 And as a further Broadcom/Avago update, the SAV540+ now replaces the ATF54143 in the VLNA preamps with proven equally good results.

Device update 2 The level 13 ADE-751MH is now offered as a replacement for the (nearly pin-compatible) level 7 ADE-13

ADE-751MH Modification Easily modified existing V1.0 PCBs

AppCAD analysis of receiver - ADE13

ADE751 mixer upgrade

Iceni noise figure and gain

Measurement of dynamic range 432.180MHz ZFRSC-42 Calibrate R&S SMG G Texscan 28.190MHz CF ICENI MI2024 HP8592L -16dBm/tone 432.200MHz -40dBm/tone With ADE13

Measurement of Rx dynamic range 2 ADE751MH Mixer

Transmit analysis – ADE751MH 432MHz 28MHz -3dBm +4dBm +17dBm -10dBm +9dBm -15dBm 0dBm Diode Diode Diplexer BPF Mixer Low PF Attenuator 432MHz BPF Tx amplifier Tx amplifier 432MHz BPF switch switch +13dBm LO Transmit chain ADE751MH 404MHz

Toko 1072A helical filters Available from RF Microwave (Frank Rota)

Transmit analysis 2 K3 2-tone drive at 50mW PEP output Spectrum from 10MHz to 1510MHz 3 rd order -40dBc/tone 0dBm IF carrier drive

Local oscillator analysis -145dBc/Hz@404MHz -144dBc/Hz 10kHz separation +12 / +13dBm at 404MHz 101MHz Butler oscillator Local oscillator amplifier LPF and BPF (SM5BSZ) x 4 = 404MHz

Local oscillator injection locking External LO input External 101MHz source Iceni

Checking phase of the two LOs 101MHz ZFRSC-42 28.200MHz R&S SMG G Extl LO ICENI #1 Dual channel 60MHz scope RF in MI2024 Extl LO ICENI #2 Ch 1 Ch 2 RF in 432.200MHz ZFRSC-42

Diversity arrangement 404MHz 432MHz

Locked dual oscillators

Summary of performance and kits Designed as a low cost but good performance 70cm transverter with 10m IF Readily upgradeable for power output using the G4BAO driver or Mitsubishi PA module Can be frequency locked with simple injection locking Two can be used for dual polarity diversity reception using common injection locking PGA432 preamplifier can be used with the Iceni to improve sensitivity At present full kits are available. With the exception of the PCB all parts are readily available from a number of sources Construction is fully documented at G4DDK.COM