Four State QRP Group

Four State

Manhattan Islander

Enhanced Manhattan Islander Audio Amp
Updated Version Of K8IQY's Famous Islander Audio Amp
Featuring K3PEG’s Enhanced Manhattan© Layout Artwork
Kitted with K8IQY, NJQRP, and NA5N Permissions
Originally Kitted by NJQRP

This Kit Has Been Retired
Kitted and Offered For Sale By The Four State QRP Group
First time builders please note: This is an ideal first kit and also the ideal kit for first time Manhattan builders. Low parts count, a great design, and K3PEG's outstanding instruction manual with a pad template make this an easy to build and successful first Manhattan project.
This kit is quite different from the retired and excellent NJQRP kit, and it deserves your close scrutiny.
Please scroll all the way to the bottom of the page to see ALL the available information.

So why the new name?
  • Enhanced The original design has been enhanced with an added preamp and the original circuit improved by Jim Kortge, K8IQY, who was the designer of the original kit and manual.   Additionally, Larry Przyborowski, K3PEG, enhanced the board design with his wonderful Enhanced Manhattan© template/layout designs.  He also wrote the outstanding assembly manual.   Larry is well known for his Enhanced Manhattan© work on K8IQY's 2N2/40+ and 2N2/20 transceiver designs.   Larry's builds won 1st and 2nd prize at two Atlanticon building contests.
  • Manhattan All Manhattan pad kit utilizing 3/16" square pads.  No Islands to cut, no drill press needed, all pads - easy construction
  • Islander ... Similar to the original Islander audio amp circuit kitted by the NJQRP Club, but with significant tweaks and improvements.
  • Audio Amp ... Yep, that's what it is.

  • Specifications and Design Features ... Very quiet noise floor, 65 DB power gain, small 2"x3" board, all Manhattan constuction, and Altoids® Compatible!.   It can be driven to about 150mw output with clean audio and room filling volume.  That much power into an 8 ohm speaker is LOUD.   The passband response curve shows a broad peak at approximately 500 - 1000 Hertz.   The input impedance is 100K for superior isolation and light loading of preceeding audio stages.   So this is a small, powerful, quiet, easy to build speaker amp which will match up nicely with your earphone CW rig.

    Documentation... All documentation, including the original NJQRP manual, is included in the kit on a mini CD.   It is very complete with K3PEG's Enhanced Manhattan© Templates, detailed step by step instructions to build it either Enhanced or regular Manhattan style, actual size templates, and excellent pictures.   Included is the schematic and Jim Kortge, K8IQY's engineering analyses with simulations, a passband response curve and transient analyses.   The amp can be built directly on Larry's Enhanced Manhattan© pictorial template with minimal reference to the written instructions if you wish, they're that good.   K3PEG's documentation is professional grade, and you will agree that it may be the best you've ever seen.   Ron Hege, K3PF, proofread the document.

    Uses ... K8IQY originally developed this little amp for speaker use with the SW+ series from Small Wonder labs.   It would be especially useful with the small transceivers that are popular today.   The SW++ series from Small Wonder Lab, DCxx series from Hendricks QRP Kits, Rockmites, the AT Sprints etc.   In addition it's useful for your bench amp, any headphone output receiver, and with suitable coupling it would make a nice headphone amp also.

    The Kit Includes ... All components, documentation, and associated parts to build the amplifier complete, less connectors and enclosure.

    Fully Illustrated Assembly Instructions From K3PEG
    Click Here To See Other Examples Of K3PEG's Enhanced Manhattan Art
    Builder's Notes and Feedback

    Completed Kit Photos By Larry Przyborowski, K3PEG

    Input End View

    Output End View

    Front View

    Rear View

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