Files covering all aspects of antenna design and installation, and solutions to problems in the RF workshop. An upgrade to the antenna modeling capacity of XLNEC released as XLNEC-2. Design below for a better Octopus tester. A complete antenna patterning range with supporting software
XLNEC-2A complete rebuild of XLNEC antenna modelling program, now in EXCEL 2003-7 form and using NEC-2. Checked in Win 10. Many new pages now including matching helps adapted from ANTENNA BUILDERS COMPANION, XLNEC pioneered use of parametric design, with automated sequential builds whilst stepping chosen parameters (included in toolbox above) A totally free NEC2 antenna modelling and matching package, unlike any other. Pre built parametric design pages for many common antenna types. All the features the average builder would expect of an antenna modelling program. (Always free since 1998)
If you do any service work, take a look at my DIY Arduino based, hand held, Octopus Tester. It has all the advantages of the traditional tester but is self contained, with no mains connect. Driven by 100 Hertz triangular wave, but easily changeable. Offered in three designs, from a simple single window traditional display, to a more comprehensive dual window version. The download package contains code for all versions, plus a comprehensive set of design notes. In all versions, all electronics sits on a proto-shield between Arduino and display.
Project:- A very useful re-design of the forever useful Octopus tester. (Arduino + Octopus = "Ardupus")
Upper side of shield holding the redesigned Octopus components.
Under side of shield holding the redesigned Octopus components.
Dual window version of Arduino based Octopus tester.
Simple window version of Arduino based Octopus tester.
The Arduino based Octopus tester, "Ardupus", received a simulation workout for a number of design options before proceeding. The accompanying notes included in the download file give more detail.
UPDATES:- Expanded projects for Antenna builders. July 2020 Updated, expanded antenna modelling program, XLNEC-2 9 Aug 2020 Introduced ANTENNA BUILDERS TOOLBOX. A suite of programs to design, build, match, and swing your antenna build. 8 Jun 29 2023 Complete rework of ANTENNA BUILDERS COMPANION
This download is a TOOLBOX containing four programs:-
1. 'XLNEC-2' A complete rebuild of my earlier released XLNEC, now in EXCEL 2003-7 form, and checked in Win 10. Many new pages now including matching aids, XLNEC pioneered use of parametric design, with automated sequential builds whilst stepping chosen parameters See above.
Project:- A COMPLETE design and test TOOLBOXfor antenna builders
Above. Arduino antenna patterning range for $100 USD
Above.Close up of display, traditional ARRL format. Pattern is saved to SD for processsing
Above. nanoVNA V2 is signal source, power is increased by 20 dB MAR amp.
Antenna pattern opened from SD. Outliers, probably caused by a 433 MHz system in my kitchen that polls a remote electric fence monitor. The workbook will enable you to filter, smooth, rotate pattern and print.
nanoVNA and ANTENNA BUILDERS COMPANION(interactive EXCEL 2007 spreadsheet format), A collection of seventy worksheets of interest to all antenna builders. Solve all the most common matching problems, and just about every other problem the antenna builder meets. The authors personal collection of solutions arising from employment in antenna manufacturing, enlarged and refined for more general use. Also a complement to XLNEC-2
SEVENTY WORKSHEETS, mostly interactive TO KNOW. Starting with sobering realities for the antenna builder. RET LOSS UNCERTAINTY. The impossibility of measuring an accurate return loss in the home workshop with nanoVNA is easily shown on this interactive calculator. BRIDGE UNCERTAINTIES. Interactive sheet to show how bridge directivity effects measured return loss. CABLE LOSS Cable loss varies by frequency and SWR. This sheet will calculate loss, eirp corrected for cable loss. K FACTOR. K factor shortening is needed for every antenna build. This calculates per formula. VELOCITY FACTOR. Needed for stubs, line transformers, and cable element calculations. Manufacturers supply this factor, but if you use covered wire or braid as a radiator, you need to experimentally determine VF. ERP EIRP Your licence sets max radiated power, effected by feed cable, antenna gain. Important in such as data links. WAVE PORTION Calculates how muich to trim to get to wanted frequency, using current resonance found by dip meter. GDO Even though later sheets show how to use nanoVNA to ‘dip’ an antenna, the Grid Dip Oscillator still has a place in every antenna builder's workshop. SMITH FORBIDDEN ZONES. When matching with the aid of Smith Chart, there are zones to avoid, and ideal combinations of L and C to move your impedance to 50 ohms. So easy to use this info in conjunction with STUB ANALYZER worksheet BROAD SMITH Broadband matches are a tricky world. Use this in conjunction with SOLVER worksheet. Even the best calculated match fails if antenna is not fully decoupled from line at every frequency. SOLVER Calculates a visual Smith Chart so you can follow effects of varying any of your matching elements STAGGER MATCHAnother visual matching aid for broadbanding. Again, even the best calculated match fails if antenna is not fully decoupled from line at every frequency. UP-LINEAn educational, interactive sheet to show how impedances change as we move upline from the source nanoVNA STUB MATCHStep by step use of R and jX from nanoVNA to match your antenna STUB PLACEMENT from R & jXThe single stub match is often used at the base of ¼ wave whips OPEN LINE STUBUsing Vmax or Vmin of standing waves on open lines to place matching stubs SMITH STUB PLACERThe most important sheet for matching your antenna using values from your nanoVNA BROADBAND STUB VIEW Interactive, but shows Smith Chart values at each point as you move thru the matching network. SERIES SECTION TRANSFORMERCoax section impedance transforms. Widely published, but rarely valuable by itself. SLUG TXFMRAnother matching technique modifying line within feed tube to avoid external stubs. Applicable to UHF COAXIAL FILTER Mechanical coaxial low pass filter designer BANDPASS Mechanical bandpass filter designer. STUB TRAPSCalcuklate a stub trap for unwanted harmonics INTERMODS Calculates potential intermods of two frequencies SYSTEM PERFORMANCE This expresses performance as uV on 50 ohm receiver load, used to be handy when talking to the old 27mHZ CB community, but a very practical way of understanding the ‘final end product’ of your system LINE TRANSFORMATIONSLine length transforms load impedance if not matched at antenna. This looks back from known load to show what has to be matched at TX end of coax TDR Just a reminder sheet. TDR is very handy for finding line discontinuities, but the nanoVNA is not yet capable of such fine resolution as to be able to show bad connectors TWELFTH-WAVE TRANSFORMERMatching with twelvth wave transformers is a useful extension of what I described earlier as ‘slug match’ MATCH BANDWIDTHFor single and double stub solutions, bandwith is calculated from the equations in Jasik’s “Antenna Engineering handbook” WHIP ANT CALCSSheet calculates needed base and elevated loading params from ARRL formulas ANTENNA GAIN Calculate antenna gain per RSSI using a Standard Gain Antenna as reference ANTENNA GAINCalculate antenna gain method two, using two identical antennas ANTENNA GAINCalculate antenna gain method three, similar method two BINOMIAL TRANSFORMER Implementing line section transformers DECOUPLING SKIRTSImportant knowledge how to build an effective decoupling skirt and skirt limitations CUT OFF CHOKE Build an effective quarter wave cut-off choke with calculated internal dielectric slug. Also calculates for half wave tube section radiators SKIRTED DIPOLEA practical build at 2400 GHz XLNEC Reminder of free antenna design /optimising software nanoVNA TECHNICALMy REM page of nanoVNA commands RESISTIVE PAD MATCHHandy pad match designer for instrumentation, not antenna SWR & LINE TRANSFORMATIONSMore line/ load calcs INSTALLATION ADVICEThings learned the hard way may save you some grief DIY ATTENUATORSCalculate resistive type attenuators SWR per ATTENUATOR Pre VNA methods for SWR, per the early Jerrold Co.notes. DELAY LINE pre VNA methods for SWR, per the early Jerrold Co.notes ANTENNA EFFICIENCYSimple explanation of antennas and power transfer MATCH BOX 1Interactive design of Matching Box outlined in old Motorola RF Power Data Manual MATCH BOX 2Second interactive design of Matching Box outlined in old Motorola RF Power Data Manual MATCH BOX 3Third interactive design of Matching Box outlined in old Motorola RF Power Data Manual ELEMENT SCALINGCalculates scaled lengths for both ‘thin’ and ‘fat’ elements ANTENNAS for DIGITALUnderstanding Inter-digital interference HELICAL ANTENNADesign sheet for helical antennas COAXIAL GAIN ANTENNADesign crossed section coaxial gain antennas correctly. The 'COCO' REVERSE ENGINEERReverse engineer a ‘Tube on Coax Core’ antenna, a common successful commercial design. REVERSE ENGINEER 2Scaled build detail for ‘Tube on Coax Core’ FAIL Designs that leave something to be desired LINE CURRENTS Line current probe to detect line currents NIST DIPOLEA pointer to Chris Scott’s ‘Measuring E-fields’ 25-1000 MHz with the NIST dipole detector’ STANDARD GAIN ANTENNABuild to formula INDUCTOR CALCSCalculator for inductors, and cavity RESISTIVE TAPDesing resistive tap attenuarors that maintain impedances at all ports. Handy for nanoVNA RESISTOR COMBINATIONSOccasionally you need an exact resistor, especially if repairing old TEK stuff, where critical values have drifted WHIP DIP Build tune and match your ¼ wave whip the best way if you wish a resonant antenna with a textbook pattern NanoVNA DIPPERYes, the nanoVNA can be used as a ‘dipper’, but operates differently to the old ‘GDO’ Here are three ways of setting it up NanoVNA DIP EXAMPLEA user example
Above:- Use the information in FORBIDDEN ZONES in conjunction with the SMITH STUB PLACER worksheet to design an optimal match.
Above:- Step stub positions and lengths using SMITH STUB PLACER to visually move impedance to center of chart using guidance from FORBIDDEN ZONES sheet
Above:- BRIDGE UNCERTAINTIES is an interactive worksheet that shows the extreme difficulty of quantifying a return loss
Above:- Consider system performance in terms of its ultimate practical value, uV on receiver load. The SYSTEM PERFORMANCE sheet calculates all path gains and losses (inc fading margin) and comes up with the answer
Above:- There are times when an exact resistor value is needed. The RESISTOR COMBINATIONS sheet calculates pairs of E12 and E24 values that get closest to wanted value
Above:- Quick design of Standard Gain Antenna, and a look at some sloppy engineering.
Above:- A better way to build a whip antenna on the WHIP DIP worksheet allows you to set the whip to resonance before matching
Above:- The CUT OFF CHOKE worksheet designs the essential internal dielectric slug needed for every quarter wave decoupling skirt
Above:- The CUT OFF CHOKE worksheet designs the essential internal dielectric slug needed for every quarter wave decoupling skirt
Above:- The BINOMIAL TRANSFORMER design worksheet
Above:- NanoVNA DIPPER sheet has suggestions how to use your nanoVNA as a Dip meter. Uses a different principle to the GDO dipper. Useful, but I still prefer the old GDO for antenna work
Above:- The INDUCTOR CALCS sheet also calculates reactances of line sections.
Pattern DISPLAY has plenty of options for producing cut-n-paste patterns for other publications
Pre built parametric builder for BACK to BACK ANTIPHASED HELICIES
3. 'ANTENNA_PATTERN_STANDALONE_320x480_V2.ino' Arduino program for a standalone antenna range.As illustrated the range will swing small antennas from 400 MHz up. For bigger antennas you will need bigger stepper, drivers, and supports but the software will remain the same. This code contains all necessary advice.The entire build should cost around $100. A low harmonic 10dBm signal source is preferred, but I here use a nanoVNA V2 feeding source antenna through a 20dB gain MAR amplifier
2. 'ANTENNA BUILDER'S COMPANION.xlsm' A large EXCEL workbook containing pages to calculate EVERYTHING you will ever need in building and matching antennas. Plenty of practical help in principles and implementation. YEARS of practical work have gone into this one. See above
4. ANTENNA FILE PROCESSOR.xlsm' will load the pattern from SD created by #3 above, clean it up, and enable you to print
: The VIEWER allows you a quick visual check of element polarities, important because it is easy to reverse a wire when building complex designs. You can instantly re color a selected wire to help troubleshoot
DECKMAKERautomatically transfers the 'Deck' to NEC2 for processing. Instead of manually building coordinates, each antenna design sheet automates, transfers coordinates to the DECKMAKER
Left. The UNIQUE feature of XLNEC is that the OPTIMISER can step through combinations of three parameters, Each step generates thumbnail pattern including gain figures, f/b ratio
Also UNIQUE are the parametric design sheets for many common, and uncommon antennas. Nominate any parameter to change, and the complete antenna is dimensionally rebuilt. A simple button press transfers the new design to the DECKMAKER SHEET
VIEW current intensity and distribution. A contribution from Chris Lord
Pre built parametric builder for . RINGO
Pre built parametric builder for PINECONE ANTENNA
Pre built parametric builder for MICRO LOOP HELIX
Pre built parametric builder for MICRO LOOP HELIX
Pre built parametric builder for BIFILAR
Above: Pre built parametric builder for LPVA, BOOM above BOOM
Right: Pre built parametric builder for SLOTTED RINDG ANTENNA
BELOW, more design sheets from XLNEC-2
Left. Pre built parametric builder for PARABOLIC YAGI
Right. Pre built parametric builder for LAZY H
Right. Pre built parametric builder for DISCONE
Right. Pre built parametric builder for VERTICAL DIPOLE with VERTICAL REFLECTORS
Right. Pre built parametric builder for SLIM JIM Lower panel shows views from other sheets in the workbook
These SCREEN GRABS from EXCEL are a bit 'ROPEY' but should give you the idea. Download XLNEC and see better for yourself.