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FA tester instructions

 

User Manual

 

 

 

 

 

 

 

 

Theo Bresler ZS6TVB

September 2020

 

Release No. Date Revision Description
1.0 2020-09-09 Initial Document
1.1 2020-09-09 Red Dots on Jumper images for clarity
1.2 2020-09-10 Corrections and optimisation by Chris R. Burger

ZS6EZ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Revision History

ZS6TVB FA Tester Instructions V1.2                                                                                                             Page ii

 

 

 

1.0 Table of Contents

 

User Manual

 

Table of Contents

 

Page #

 

  1. General Information………………………………………………………………………                                                                                                                      A-1

1.1  Background ………………………………………………………………………………                                                                                                                      A-1

  1. Using the FA Tester……………………………………………………………………….                                                                                                                      B-1

2.1  Connecting to your Vector Network Analyser …………………………….                                                                                                                      B-1

2.2  VNA Calibration………………………………………………………………………..                                                                                                                      B-2

2.3  Test your Device ……………………………………………………………………….                                                                                                                      B-3

2.4  Additional Applications ……………………………………………………………..                                                                                                                      B-3

  1. Miscellaneous ……………………………………………………………………………….                                                                                                                      C-1

3.1  Acronyms and Abbreviations …………………………………………………….                                                                                                                      C-1

3.2  Contact Me……………………………………………………………………………….                                                                                                                      C-1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ZS6TVB FA Tester Instructions V1.2                                                                                       Table of Contents

 

 

 

A  General Information

 

 

 

  1. GeneralInformation

 

1.1        Background

 

ZS6TVB designed the FA Tester as an Amateur Radio weekend project to

provide a means of simple and easy testing of QRP Labs filter board kits

and other filters or attenuators in a similar physical format.

 

Connecting cables and connectors to the filter kits for testing or calibration

of a Vector Network Analyser (VNA) is challenging. The FA Tester is

designed to enable filter kits and attenuators to be tested accurately and

repeatedly with a VNA, providing the correct calibration plane with on-

board calibration jumpers and termination resistors. The design was kept

simple with a single-layer PCB. Tracks were kept as short as possible for

accurate testing at higher frequencies.

 

The design is not intended as a commercial product. It is for testing

personally acquired QRP Labs kits. Use the board at your own risk.

Accuracy is not guaranteed.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ZS6TVB FA Tester Instructions V1.2                                                                                                           Page A-1

 

 

 

B  Usage

 

 

  1. Usingthe FA Tester

 

2.1 Connecting to your Vector Network Analyser

 

The FA Tester features two standard SMA-F RF connectors: One each for the

S11 and S21 ports on your VNA. Depending on your test equipment or

requirement for the device being tested, the FA Tester may be connected to only

the S11 port or to both ports of your VNA.

 

Your VNA should have been supplied with two SMA-M to SMA-M pigtails that

may be directly connected between the FA Tester and your VNA without the

need for any extra connectors. Connect the FA Tester S11 port to your VNA S11

or CH0 port. Connect the FA Tester S21 port to your VNA S21 or CH1 port.

 

Should you have a modern VNA such as the NanoVNA range with the 4” display,

you may use the pigtails supplied with your VNA or connect directly to the VNA

with the use of two SMA-M to SMA-M barrel connectors. The FA Tester was

designed with the same spacing between the two SMA connectors as provided

on the more modern VNAs, so that the FA Tester can be connected directly to

the VNA. Refer to the image below for more detail.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ZS6TVB FA Tester Instructions V1.2                                                                                                           Page B-1

 

Calibration Sequence S11 Jumper Position S21 Jumper Position
Open O O
Short S O
Load L/I O
Isolation L/I I
Through T T

 

 

B  Usage

 

2.2        VNA Calibration

 

To aid accuracy, the FA Tester is equipped with matched 50 Ω resistors on both

the S11 and S21 ports. A complete calibration sequence for Open, Short, Load,

Isolation and Through may be done by simply by placing the S11 and S21 jumpers

at their correct locations. Jumper positions are clearly marked on the board for

correct placement. Refer to the table below as a reference of where jumpers

should be placed during the calibration sequence of your VNA or VNA software.

The images below should provide more clarity.

 

Note: Once the calibration process is complete, remember to place both

jumpers back into the Open (O) position.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ZS6TVB FA Tester Instructions V1.2                                                                                                           Page B-2

 

 

 

B  Usage

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2.3        Test your Device

 

Finally! Time to start testing.

 

  1. Ensureboth S11 and S21 jumpers on the FA Tester are placed in the Open

(O) position.

 

  1. Ensurethe filter is plugged into the FA Tester and that the IN and OUT

sides of your filter are aligned with the IN and OUT markings on the FA

Tester.

 

  1. Proceedwith testing of your device.

 

Actual tests are outside the scope of this document.

 

 

 

2.4        Additional Applications

 

Although originally designed to test filters, the FA Tester may also be used to

accomplish the following tasks.

 

• With both jumpers in the Open (O) position, connect your filter to a coaxial

transmission line.

 

• Use it as a calibration standard for your VNA or Antenna Analyser.

 

 

 

 

ZS6TVB FA Tester Instructions V1.2                                                                                                           Page B-3

 

 

 

C  Glossary

 

 

  1. Miscellaneous

 

3.1        Acronyms and Abbreviations

 

Acronyms and abbreviations used in this document:

 

PCB:              Printed Circuit Board

RF:                  Radio Frequency

SMA:             SubMiniature version A

SMA-F:       Female SMA

SMA-M:      Male SMA

VNA:              Vector Network Analyser

 

 

3.2        Contact Me

 

Should any of the content in this document not be clear you are welcome to

contact me. I am on QRZ.com.

 

73

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ZS6TVB FA Tester Instructions V1.2                                                                                                           Page C-1

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Q80 add-on for Q40 End Fed Halfwawe Antenna

80m Add-on

HOW TO OPERATE THE “Q-40”or 40m EndFed Antenna ON 80 METRES

A loading coil must be added to a 40m  to operate on 80M. The overall length of the 80-10M version of this antenna is about 23 metres. See details below:

The nominal inductance of the loading coil is 110 μH to cover the 80m band. Use 50mm PVC plastic pipe for this coil. The PVC pipe needs to be about 70 to 80mm long, to allow for attaching strain-reliefs. Shrink tubing can be used for weatherizing (note that this changes the inductance slightly – but is not serious) the shrink tube openings of the coil can be made watertight by stuffing it with hot-melt glue from a glue-gun just before applying heat to the shrink tubing. You need to make this loading coil as waterproof as possible.

Use 0.7mm Ø enamelled copper wire. Wire length needed is about 8.5 metres, make it 9.0 metres. With 52/53 turns, and tightly wound, the coil takes up about 40mm of space. Measured 110.7uH on my inductance meter. Instead of wrapping red wire around the ends, rather use suitable plastic cable ties. I went to an electric motor repair shop to get the wire. If you have one of my LC Meters, you can measure the coil exactly!

Figure One: Typical loading coil.

Figure Two: Typical Antenna Layout.

Tuning the total antenna. Standard approach for tuning-and-pruning the antenna is to start with the band where the antenna acts as a 1/2-wave end-fed (40 metres for the 80-10 antenna). Measure the SWR in the portion of the 40 metre band that is of interest. Without an antenna analyser, this is do-able but definitely not easy…. If the frequency of the SWR dip is above that band portion, then increase the long wire by 5 cm at a time and repeat the measurement. Conversely, slightly decrease the length of the wire if the SWR dip is below the band portion of choice. Repeat until the minimum SWR is achieved. Now add the loading coil and 2.4 metres of cable. Then follow the same procedure for adjusting the 80 metre length of the extension wire for minimum SWR on the portion of the 80 metre band of your interest. Just fold back the excess and wind around onto itself. So it is best to start out with wires that are definitely too long. Do your SWR measurements on 7.100 MHz for 40m and 3.65 MHz for the 80m tuning operation.

Depending on your local environmental conditions you may have to use an antenna tuner for best results.

The typical layout shown above does not necessarily have to go over a house roof – this is just an example. I have hung the transformer box under the eaves, and strung the cable from an upstairs room and over some trees and bushes at a height of about 5 meters, and it worked beautifully.

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QRP-Labs QCW Band Conversion

QRP-Labs QCW

The CW Kit from QRP-Labs is a very capable transceiver and the performance matches just about anything available on the market.

There is a small problem, however, with the fact that it is a single-band device. So when I stared out I built a 20m unit which has been remarkably fun when the bands are open, but mother nature isn’t always kind to us and often times there was just no signal to play with.

So, I investigated what is required to change it down to 40m. Turns out it isn’t a lot. A few toroids, a few caps. Most of the components can be desoldered without hassles. My initial take is that the following components are affected:

  20m   40m  
L1 0.77uH 16 1.4uH 21
L2 0.90uH 17 1.7uH 24
L3 0.77uH 16 1.4uH 21
L4 0.40uH 10 1.0uH 16
C25 390pF “391” 680pF “681”
C26 390pF “391” 680pF “681”
C27 180pF “181” 270pF “271”
C28 180pF “181” 270pF “271”
C30 30pF “300” 56pF “560”
C5 none none 40m 39pF
C8 none none none none
T1 3t x 3 30t 5t x 3 38t
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New News

Radiowinkel is the start of a new multi-language version of Radio-Shop. In theory – if the software works – most pages will be translated and kept in sync auto-magically. But you never know what can happen in the deep dark depths of the internet, so when you notice a problem please let us know?