Episode 265 – Eric Sears – ZL2BMi
Eric Sears, ZL2BMI, who joins me from New Zealand, is famous for this 80 meter QRP double sideband rig that he designed and documented in the 1980s for his personal use when “tramping” in the forests and mountains of New Zealand. Eric’s stated design philosophy and rigs proved to be robust and foundational for other QRP rig builders, especially in the southern hemisphere through the years.
QRZ Off-Track ZL2BMI Double Sideband QRP Transceiver
First License: Zl2UBG, Technician, 2 meters and above
ZL2NBI, Novice license concurrently to operate CW in low bands
First Rigs: Pye Hearld tube FM VHF ZC1 Transceiver HF, New Zealand war time radio Ten-Tec Argonaut HF Transceiver
Current Rig: Kenwood TS430 HF SSB Homebrew rig Yaesu VX5 VHF
Favorite operating mode: · 80 meter DSB QRP Backpack portable
ZL2BMI Design Philosophy
Having only very limited equipment and being quite hopeless at most metalwork, the following were important:
Small size and light weight (for tramping)
Battery economy ‘
Voice’ transmission (with C.W. if required)
Ease of construction.
A.M. was feasible, but heavier on battery and not so compatible with S.S.B.
SSB was too complex to produce.
DSB (at low power levels), is simple to produce and economic in terms of battery drain.
People: XYL: Mary Sears, ZL2TFS Mentor: Roger Lawson, ZL2BHG Bob Sewell, ZL2ASO – Wellington 92 years of age Bill Meara, N2CQR Doug DeMaw, W1FB Peter Parker, VK3YE
Radio Discussed: Hiker’s One – one tube radio transceiver Foxhole radio crystal radio 48 Set HF Transceiver 5 mhz. Peter Parker’s VK3YE’s DSB rig SSB Transceiver using DDS Elecraft KX2 QRP transceiver
Terms: Boy Scouts New Zealand Semaphore signaling Morse Code Blue razor blade White spot transistors New Zealand Army Cadets New Zealand Citizens Band, AM on 26 Mhz New Zealand Backcountry Hut Double Sideband suppressed carrier New Zealand Forest Service backcountry huts Anglican Church ministry “Ham Cram” licensing New Zealand Nation Amateur Repeater System New Zealand Association of Radio Telephone Break-in Magazine Dick Smith Electronics Covenanted properties G-QRP Club SPRAT magazine NE602 Mixer Double balanced mixer Ugly bug electronic construction Dead bug electronic construction Solder Smoke Podcast 80 meter end-fed wire antenna
Greatest challenge facing amateur radio now: Proliferation of communication, cell phones.
Most excited by: In an age where everything is regulated, as hams we have the freedom to build our own gear.
Advice to new or returning hams: Don’t just be an operator. Learn a bit more about simple circuits.
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ZL2BMI HF Transceiver
ZL2BMI DSB Transceiver Top View
Ten-Tec Argonaut HF Transceiver
ZC-1 HF Transceiver