1. README

2. WAVE PORTION

Use for instant calculation of commonly used wave portions in air and cable.

Uses include calculation of stacking distances, calculation of quarter wave stubs, and whip

lengths.

3. ERP/EIRP and CABLE LOSS

This sheet lets you see actual cable loss, and its effect on ERP for a range of

standard cable types, at your selected frequency and desired cable length.

You can also enter cable specs for cables that are not listed, and obtain the same

information. For this you only need to enter manufacturer's data of cable loss at any two

frequencies. No twelve digit ‘factors’ are required!

4. ERP/EIRP and SYSTEM ANALYSIS

Calculator allows entry of essential system parameters, and gives indication of signal

available at receiver. Takes into account Tx power, Tx cable losses, Tx antenna gain, Balun

and Filter losses, and Connector losses. Free space losses are calculated, and Rx antenna,

feed cable and other losses are considered to finally give estimated 'uV on 50 Ohm receiver

load'. Fading margin can be taken into consideration if desired.

Cable losses for Rx and Tx feeds are pre-entered for RG213, but details for any cable

can be entered as long as losses at any two frequencies are known. These are generally

available from manufacturers spec. sheets.

5. TWO WAY SYSTEM PERFORMANCE

A similar calculation to the above, but set out differently.

After entering all the factors normally taken into consideration for analysing your two-way

system performance, expected signal strengths received both at base and mobile are given. The

effect of any change to any system parameter can be instantly evaluated. Additionally, line

of sight is calculated taking into account earth's curvature and antenna relative heights.

This sheet also separately calculates received signal strength where antennas are not

optimally aligned, as at 3dB fringes (or other chosen reference).

YOUR TWO WAY SYSTEM MUST BE PLANNED WITH THE SERVICES OF A COMMUNICATION ENGINEER, AND GOOD

PRACTICE WILL USUALLY CONFIRM THE DESIGN WITH FIELD TRIAL.

6. MICROWAVE SYSTEM ANALYSIS

Using standard equations for obtaining received signal strength in a Microwave system.

Results from several accepted methods are presented.

For those who use a GPS for quick determination of location, Great Circle distance, and

Azimuth calculations have been added to the lower portion of this sheet.

ALL ASPECTS OF YOUR MICROWAVE SYSTEM MUST BE PLANNED WITH THE SERVICES OF A COMMUNICATION

ENGINEER

7. SWR HINTS for WHIP INSTALLERSQuick assistance for determining whether whips are long or

short. Includes a ratio calculator to estimate amount to trim (or add!) to a whip to bring it

into tune.

8. COAXIAL CABLE INTERFERENCE TRAPS

Often a simple stub trap on a feedline can deal with interference. This sheet makes the

options clear. Often there are choices other than a simple quarterwave trap.

9. INTERMODS

Enter two frequencies, and instantly see all intermod. products to fifth order. Very

handy for checking potential problems in advance of installing. Some useful products

resulting from combinations of three frequencies are given.

10. SWR CORRECTION for LINE ATTENUATION

Long, lossy cables mask a high VSWR at load. This calculator gives true VSWR at load,

for a range of cable types when VSWR has been measured at transmitter end.

12 INSTALLATION ADVICE

Head off intermods and call-backs with good installation practice. A simple list of

things to attend, to ensure a good installation.

13 KNIFE EDGE

Often diffraction over an obstacle is needed. The losses are high, and some basic

criteria need be satisfied.

Edge to be greater than 100 wavelengths long, a minimum of 100 wavelengths high, and the

closest station to be distant from the edge a minimum of ten times the edge height.

Caution:- Very few natural obstacles form an ideal diffracting edge, and you would not plan a

system on the figures calculated without an actual field assessment.

14 FRESNEL ZONE

This worksheet allows the calculation of clearances necessary along a radio path to

avoid the losses. As obstructions within the first 0.6 Fresnel zone cause the greatest

losses, and this is calculated for you for line of sight paths. You require to enter the

distance of a chosen point from each end of path. the program calculates the clearance each

side of path center needed at that point. You may also calculate other Fresnel zones using

this page.

15 POWER DENSITY

Information re. calculation of Power Density in the Far Field. Preliminary calculations

are possible on this sheet, but compliance with a standard is a job for a certifying

laboratory.

1. RET. LOSS MEASUREMENT UNCERTAINTY

This is not the type of calculation most of us need on a daily basis, but the sheet is

really an easy way to EDUCATE that return loss (and hence VSWR) is a measurement that has

potential for high uncertainty. By simply entering figures from your equipment manufacturer,

and exploring some values of VSWR for your Test Port Adaptor, it will become very clear that

IMMENSE uncertainty can arise from using cheap adaptors, or worn adaptors between test port

and load.

On occasions clients have said, "Our SWR measurements are not the same as yours". A

knowledge of the uncertainties involved will soon help you understand the fragility of VSWR

readings when not made under laboratory conditions. And even then!

2. VELOCITY FACTOR

A halfwave length of coaxial cable when shorted will show a voltage null at the

feedpoint. The exact frequency of this null, in conjunction with measured line length is used

to calculate the velocity factor of the cable. Experience has shown that antennas designed

using cable sections can give problems if using a substitute cable, and simply assuming the

VF is as expected. Some may prefer the errors to be treated per RSS .

3 STUB ANALYSER

Gives results equivalent to the proprietary "Smith Chart". Match Load to line with this

interactive tool, using one or two stubs. Naturally, load must be known.

4 STUB ANALYSER 2

Once R and jX of load are known, this enables exploration of size and placement

solutions for single and dual stubs.

5. STUB PLACEMENT from R and jX

Any time R and jX of load are known, stubs can be calculated and placed mathematically.

6. STUB PLACEMENT from R and jX (2)

As above, but different types of stubs are explored.

7. SLOTTED LINE (Uncorrected)

Using figures for your load obtained from a slotted line measurement, automatically gives

stub placement and dimension.

For ‘homebrew’ slotted lines, calculation of VF is possible from line measurements, and a

portion of this worksheet does this for you.

8. SLOTTED LINE, w/DIODE CORRECTION

Slotted lines can be purchased as ‘lab’ items, or constructed by slotting a 9.5mm od.

Tube, and filling it with a RG213 core. A simple saddle with a voltage probe can be made up.

If a current probe is used, remember that a current minimum represents the voltage maximum

needed. This technique is accurate enough for stub calculations, as some field adjustment is

always needed and should be allowed for in stub selection.

This sheet allows the calculations to be automated. If used with a HP805 line, a diode

corection curve is applied, to greatly reduce ‘square law’ errors.

The program calculates a correct stub solution for your match.

9. SLOTTED LINE, using ATTENUATOR

A slightly different technique, using an attenuator, allows any detector to be used on

a slotted line, and detector errors are avoided.

10. SERIES SECTION TRANSFORMER

Calculations for those who wish to use series-section line transformers for matching.

11. SLUG TRANSFORMER CALCULATOR

Slugs of varying ‘e’ inserted as sliding elements in a section of constructed

transmission line give matching opportunities. This sheet allows interactive exploration of

possibilities.

SLUG TRANSFORMER DESIGN NOTES ‘README’

Design notes for practical implementation of the slug match to a feed tube to a

colinear antenna

12 POWER DIVIDER DESIGNER

Further design material for power dividers.

13 IMPEDANCE CHART

A simple chart in the traditional format, allows plotting of three measured impedances.

This sheet is included basically to allow perusal of the VBA code by those interested in

seeing how the chart works.

14 SOLVER

Broadband matching is always tricky. Improvement at one end of the band invariably

results in problems elsewhere. This sheet allows selection of elements to be assessed

visually, and values to be stepped. Used similarly to the ARRL program ‘Microsmith’, Load is

at left hand end.

‘Lumped 1’ is lumped element at load. Directly underneath is where you declare type and value

of the element you are adding, if any

‘Line 1’ is a line section. It may be of any declared impedance and length.

‘Stub 1’ is either a series or parallel stub.(or no stub at all)

‘Lumped 2’ gives opportunity to add a lumped element at this point instead of a stub.

This pattern can be continued, and the final impedance at end of feed line appears at the end

of line three.

Basically, this combination of possible setups will offer the possibility of achieving any

possible broadband match.

In the words of one of Australias foremost RF engineers, ‘There are infinite match

possibilities, but only one is optimal’ .. I leave it to the reader to ensure that the

selected match is stable enough to be practical.

My advice is that when using the step feature on this sheet, and your marker goes

through the chart center like a comet when you click the mouse to increment a value, then

it’s time to start again!

I urge users to read ARRL publications, especially information on ‘Outer Boundary’

Users of this page will find a useful chart for forming various impedance line sections

from brass stock commonly available. These line sections are very commonly used in industry,

and deserve serious consideration in seeking matching solutions.

The sheet is designed for broadband matching, so entries should be made at mid

band, and at band ends. If a single entry only is used, use the topmost entry row. Some

garbage will appear in odd boxes. If you check the code, Excel has been told not to display

in this case, but does it anyway!

15. HP803 BRIDGE

Still a few of these bridges about, and this page Illustrates how the tedious

calculations associated with their use can be reduced to a simple spreadsheet exercise.

16 STAGGER MATCH

A simple adaptation of work by Henry Drillich in his paper to the Australian Electrical

Engineering Congress, Nov 1984, entitled 'A New Approach to Modelling Complex Impedances'

.. Here we use two consecutive sections that match the load at offset frequencies to

efectively broadband our match.(Rather like we used to step-tune IF transformers to get the

IF passband characteristic we needed) Because this page is specifically designed to provide

matching solutions that will suit the feed tube of coaxial gain antennas that are fed from

the bottom via a metal 50 ohm coaxial section, both the matching sections consist of a line

section followed by a closed stub.

17 UP-LINE

When we make measurements along the coax from the load, we need to apply transmission

line equations to ascertain load values. This sheet will allow you to look up-line to the

feed point

18 SITEMASTER' STUB MATCH

Working the above concept, from values ascertained by the ‘sitemaster’, we look up-line

to the load feed point, and calculate appropriate stubs and their placements.

19 IMPEDANCE MATCH for INSTRUMENTS

Resitive matches for instrumentation purposes

20 DIRECTIONAL COUPLER

This simply constructed directional coupler is amazing. The core element costs but a

few dollars, and comes from high quality TV splitter. The results obtained equalled in every

way a commercial $A3000 unit to 500 MHz. Care in construction is essential, and in use, a 6

or 12 dB attenuator must be used at Source input and Detector output, and a precision 50 ohm

termination is needed for the Reference. With a little more thought to construction, I expect

this design is useful to 1 gHz.

21 TWELFTH-WAVE TRANSFORMER

Interesting comments, and a calculator for those interested in exploring the twelfth

wave transformer.

22 TRANSMISSION LINE

A few handy calcs for making / analysing transmission lines.

23 QUARTER WAVE TRANSFORMER

Calcs for making and using quarter-wave transformers.

24 TRANSFORMER and STUB

calcs for designing broadband matches with quarterwave transformer series and shunt

calculations.

25 MATCH BOX 1

26 MATCH BOX 2

27 MATCH BOX 3

These automate calcs for the matching sections in the ‘Motorola’ Handbook

28 QUARTER-WAVE BINOMIAL TRANSFORMER

Balanis, "ANTENNA THEORY", 2nd Ed Sect. 9.8.2, sets out matching ideas for quarterwave binomial transformers. A

note in this page of calculations contains a caveat

1 COAXIAL GAIN ANTENNA

Crossed cable sections provide the basis of an antenna that has been around for a long

time. Easy to build, and gives good, tight gain patterns.

2 HELICAL ANTENNA

A complete calculator for helical antennas. Allows design offset to allow for pull down

effect where the coil is wound on PVC tube with wire or copper tape. From experience, a 2400

helical wound on 38mm PVC using ¼” leadlight foil, needs to be designed for a 20% higher

frequency. For winds with 1mm wire you would do your first trial design at 10% higher. The

most interesting result of my work in this field, is to show that the use of reduced ground

planes can result in very effective point to point link antennas, at 2.4 gHz, that can be

totally enclosed in a 50mm PVC tube.

Matching of these foil wound antennas is a lot easier than current articles suggest. Simple

tabs up from the groundplane, placed by trial and error (in conjunction with the scalar

analyzer) work fine.

3 STANDARD GAIN ANTENNA

Calculator for building the Standard Gain Antenna, and a few comments re the design!

4 DDDR

Some calculations for DDDR antennas, loop ring elements

and calculations for constructing the anti-phased helical.

Whilst the anti-phased helical antenna is most often used in broadcasting, the design

could have use where a high gain antenna is needed for broadband use, as in SCADA

systems where TX/RX splits may be 75 MHz. Whilst I have not fully trialled this design,

a 6 dBd prototype for 900 MHz was built prior to my retirement. Later it was spun on

the range, and reports were that the pattern was ‘tight’. The intention was to try and

produce a design that would service the 853 - 927 MHz split of a local SCADA

allocation. Getting an effective broadband match with this split, on a colinear 6 dB

gain antenna had proved daunting, as had keeping a reasonable gain (pattern) at band

ends.

5 BICONICAL

Analysis of the Biconical is well covered in Jasik, ‘Antenna Engineering Handbook’, so

by calculating his ‘Ka’ factor, proposed broadband designs can be assessed from his published

patterns.

6 MICROPATCH ANTENNA

Calculator for a simple 6 dB patch antenna.

7 BEAMTILT

Calculator for designing beamtilt into a phased array. Includes commnt on beamtilt in

vertical colinear antennas.

8 POWER DIVIDER

An aid to designing traditional power dividers using metal tubing.

9 POWER DIVIDER DESIGNER

Some notes on an experimental power divider

10 ANTENNA SCALING

Re-scaling an antenna to a new frequency requires attention to scaling every dimension,

and this sheet is to assist.

11 K-FACTOR

Calculate ‘K’ factor for shortening ‘thick’ antenna elements per formula.saves

interpolating the ARRL chart!

12 SLUG COMPENSATION:- CUT OFF CHOKE and CABLE SECTION 1/2 WAVE RADIATORS

Vertical skirted colinear designs can fail because of a lack of understanding that ‘K’

factor reduced resonating elements do not naturaly form quarterwave cut-off chokes. A

compensating slug is needed, and can be calculated.

13 ANTENNA GAIN (Method 1) Calculating antenna gain using several different methods.

14 ANTENNA GAIN (Method 2)

15 ANTENNA GAIN (Method 3)

16 SWR via ATTENUATOR

An old method of calculating VSWR using a delay line and attenuator avoids ‘square law’

errors

17 THIRD HARMONIC

calculator for an old method of supressing third harmonic.

18 YAGI MAKER

Automate the calculations for yagi elements.

19 DIPOLE BANDWIDTH

Calculateds an estimate for dipole bandwidth. Borrowed, with acknowledgement.

20 WHIP ANT CALCS

calculate loading inductances as loading coil is moved up the whip.

21. NIST DIPOLE

calcs for the NIST reference dipole.

22. ANTENNA EFFICIENCY

Explaining energy capture at HF and UHF

1 PASSIVE FILTERS

Calcs for simple L / C filters

2 HANDY CALCULATIONS for the WORKSHOP

A page containing many small calculators needed occasionally in the workshop.

1. dBm to mW

2. Ret Loss from SWR

3. SWR from Ret Loss

4. Attenuation from SWR

5. Attenuation from Ret Loss

6. dBm to V rms, 50 ohm system

uV to dBm, 50 Ohm system

Resistive Attenuators

'T' type

'Pi' type

8. R/C Time Constant

9. Output and range from a Voltage Divider

10 DC Clamp voltage for Surge Supressor

11 Convert Signal to Noise plus Noise ratio, to S/N Ratio

12 Power After Attenuation or Gain Stage

13 Power in 50 Ohm system with Mismatch Power Head

14 Attenuator Needed to Improve Source Match of Generator

15 Improved Source Match of Generator

16 Coaxial Line Impedance, normal Concentric Line

17 Coaxial Line Dimension, Impedance and Inner Known

18 Coaxial Line Dimension, Impedance and Outer Know.

19 Means

20 Lathing. Stock removal calcs.

21 Delay Line length

22 Convert Grains to Grams

3 MEMORY JOGGERS

Resistor color codes, and capacitor values

4 RESISTOR COMBINATIONS

An automated calculator for determining parallel combinations of resistors to obtain a

desired value. E12 and E24 series

5 INDUCTOR CALCS

calculator for solonoids, cavity, and transmission line elements.

6 STRIP INDUCTOR

When building amplifiers 1700 and 2400 MHz, strip resonators were very easy to build

once the basic design had been tracked. These graphs should assist those working at these

frequencies.

7 WINDLOAD, YAGI

8 WINDLOAD, VERTICAL ANTENNA

Basic assistance in calculating windload

9 DELAY LINE

calculate line lengths for desired delay.

10 POWER METER

On occasions a calibrated signal gen. can be used to calibrate old diode detectors to

enable their use to make (low)power measurements. Useful, in conjunction with reference

loads, for verifying that power dividers are actually dividing evenly.

One thing to check with these old detectors, is that they are still 50 ohms!. If

‘burnt’, they may be way off. My advice, after being ‘burned’ myself, is to give these a

simple ohm-meter test before forking out any money!

11 NICAD PACK CAPACITY CORRECTION

Manufacturers specify capacity at a specific discharge rate, and temperature. We often

test at different rates and temperatures. This sheet is an attempt to correct our

measurements for rate and capacity, and was used as the basis of a simple nicad tester for a

government service who had set a ‘throwaway’ baseline at 80% rated capacity.

12 NOISE GENERATOR

A simple white noise source. Because your source should be 50 ohm, the output should be

used with a 12 - 20 dB attenuator. The noise from the transistor equals that from the special

noise diodes that I have. I decided to build a high power unit with a string of MMIC’s, to

use with a bridge. After a week, I decided it was best to buy a commercial unit!

13 IN-LINE AMPLIFIER

Design idea for a coaxial amplifier

14 OP AMP

Calculator for op-amp elements.

15 TDR

Reflected signals contain important info that can give important circuit info. This

field is made understandable in the reference material contained within the old HP ‘1S1’ and

‘1S2’ TDR ‘scope plug-in manuals, and well worth chasing up.

The helical antenna described earlier, wound on PVC tube was examined with the TDR

capability of the 1S2, and verified the even transition of impedances from 50 to 120 ohm at

about four inches up the spiral.

16. RSSI CALIBRATIONS

By stepping a calibrated signal generator feeding into a receiver with RSSI, a

calibration curve can be derived. (Give due care to impedance matching!)

Several programs, such as ‘KyPlot’ and ‘DPlot95’,will convert this data to give an

equation for the curve.

Using this curve, and again paying attention to matching, your receiver can be used for close

to lab quality measurements. The only thing to watch is that your measurement range does not

straddle an internal electronic band change.

A typical curve for an ICOM R7000, and WINRADIO card is given. Note the WINRADIO data

is returned as raw 8-bit data, and is of not much real use. Adequate settling time is needed

on both these receivers, and after a set of experiments with a high speed aquisition card

(LABCARD PCL-818), I suggest 80 msec is needed for both cards.

17 VSWR REFERENCES

Handy ‘general purpose’ VSWR references can be made from attenuators and loads found in

most workshops.

18 ICOM C STUFF

Routines in Microsoft C to enable setting of frequency and mode in an ICOM R7000, via a

‘C1-V’ interface. I use this to step the ICOM at the same time as the R&S ‘SMS’ sig gen. The

RSSI resulting is read on a PCL-818 Labcard, enabling me to plot VSWR’s via a bridge.

19 NICAD DISCHARGER in C

The TL549 a/d converter chip is ideal for applications where eight bit accuracy is ok.

Here is a simple circuit where a Nicad pack is discharged via a load (R1), and the pack

voltage is read via LPT1

20 GRAPHS in C

My routines for Microsoft ‘C’ to place a graticuled display on your PC, and plot data.

21 PORT READS in C

Some routines for port reads in ‘C’.

22 HANDY C

Just some routines to do odd jobs,in ‘C’.

23 PORT I_O

Port reads are available in Win95/98. This page, and the associated code module shows

how to do it, via a publically available DLL. Required is Win95io.dll, which is included in

RF2.zip.

24 OPTO and SMS CONTROL

An encouragement to use older equipment, with a bit of modern technology to assist. The

advantage of writing your own code is that displays/reports can be exactly what you want.

25 COST SHARE

Only included to show that simple, neighbourly problems, are occasionally well

solved with the power of Excel.

26 CYLINDER HEAD FLOW BENCH

Excel provided a low cost way of analyzing results from a cylinder head flow bench.

Build details are alluded to, and the clever person should find sufficient detail to

replicate the project. The major difficulty will be finding a GM-671 blower, driving it with

a single phase motor, and finding neighbours that will tolerate the noise!

27 FOUR RUN BALANCING

Graphical and mathematical solution to dynamic balancing of a turbocharger rotor. Client had

built a wonderful balancing machine that was the equal of any commercial machine on offer,

looked to me to provide the electronics, and assistance! Whilst I knocked up this sheet for

the client, have not yet had reports, as the ‘two run method’ was working well.

28 STEPPER MOTOR

Some calcs arising from the need to assess the size of stepper motor needed to drive

the table of an X-Y-Z table we have put together for PCB milling.

29 RC FILTERS

Calculates elements for a notch filter from ‘National’ handbook

30 NF105 SIG STRENTH

Automates field strength calcs for the old Singer NF105

31 TX HARMONICS

Often a ‘spot’ source can be obtained from a harmonic of an existing oscillator, or

junkbox crystal.

32 555 CALCS

A couple of ‘555’ relates calculations

33 HP5257A

Using these old counters required a little calculation ability. Worth keeping if you

had the Type M with its high stability option.

34 WINRADIO RSSI SETTLING

This sheet came together as I attempted to use the RSSI as part of an instrumentation

project. Eight bit resoloution, and a 75 millisecond settling time killed it.

35 CAPACITOR CALCS

Capacitance calculator. Handy for the Tesla fans.

36

37 ANTENNA FACTOR

calculator for Antenna factor

38 TUBE TRANSMISSION LINES

Some calculations for calculating impedance of odd line sections. Basically, this was

used to help evaluate the useability of drums of ‘imported’ RG213 that had a central core

with very offset conductor.

39 ELEMENT COMPENSATION

When yagi elements go through a boom, a length correcytion is needed. This is borrowed,

with acknowlwedgement.

40 CAPACITIVE DISCONTINUITY

Adding series section transforming pieces in a line introduces step discontinuities.

Effectively adding a capacitance. This is a calculator for the capacitance value.

41 EQUIANGULAR SPIRAL

Co-ordinate generator for these spirals.

42 ATTENUATORS

Calculator for PI attenuators.

43 FUSES

Calculate wire size for wanted fuse.

44 COIL DESIGNER

Design air spaced coil, to 60 MHz, or analyse an existing coil.

45 DATA SLICER

To analyse data coming back from a 27 MHz control link, we had to translate the data

stream from the ICOM R7000 into a readable stream. This slicer worked perfectly.

46 NOISE FIGURE

Noise measurement calcs for an AILTECH receiver.

47 FOLDED DIPOLE

Several calculators for feed point impedance of folded dipole.

48 INSTALLATION WOES

Just a story of trouble, where the job seemed so basic!

The old RF1, RF2, RF3, RF4 files covering all aspects of antenna design and installation, and solutions to problems in the RF workshop. They now suit Excel 7, and an upgrade to the automated antenna modeling capacity of XLNEC, which integrates EXCEL and the NEC engine

Left: Among other features, XLNEC will step a frequency range, generating thumbnail patterns at each step.

Right: The VIEWER allows you a quick visual check of element polarities, important because it is easy to reverse a wire when building complex designs.

Right: The VIEWER allows you a quick visual check of element polarities, important because it is easy to reverse a wire when building complex designs.

Slug Match in practice. Some dielectric is removed from the core in this 2.4 GHz feed, which leaves a section where a section of dielectric can be slid with the aid of a pin. Appropriate techniques can be investigated with the aid of RF2.XLS, Worksheet #11 and 15

Helpfile for **XLNEC** is included in the above ZIP, but best to read first..