KANGA PRODUCTS QRP Desktop Pocket Transmatch Instructions
- June 13, 2024
- KANGA PRODUCTS
Table of Contents
KANGA PRODUCTS QRP Desktop Pocket Transmatch
Product Information
The Kanga QRP Desktop/Pocket Transmatch is a versatile tuner available in two different designs. One design is suitable for use in a shack and can be placed on top of a FT817/8 or similar devices. The other design is more compact and designed for field use, with top-mounted controls. Both versions of the ATU work the same and are designed to operate from 3.5MHz to 30MHz. Some customers have reported successful use on 6m as well.
This Transmatch is designed to be user-friendly, providing easier operation compared to many manual ATUs. When tuning, it is recommended to reduce output power if possible to be considerate of other Hams. A watt or two should be sufficient. If you are using a coax-fed antenna, ensure that you select “Un- Bal” on the rear panel switch. If you are using a balanced feedline, set the switch to “Bal”.
Product Troubleshooting
If the LED is very dim at all settings of the controls, it may indicate that the sensitivity trimmer is set too low. The LED receives power from a voltage produced when there is a mismatch. To adjust the LED’s sensitivity and brightness, locate the small trimmer on the main PCB and adjust it accordingly. It is recommended to set the sensitivity to maximum (or just below) for a bright LED. With a low-power carrier applied, fine-tune the trimmer for optimal LED brightness. If you are unable to tune an antenna on a certain band, ensure that you have an adapter to connect a balanced feeder to the ATU. In this case, switch the rear panel switch to “BAL”. Normally, it should be set to “Un-Bal” for coax feeds.
Introduction
The new Kanga Transmatch tuners are available in to different designs, one is more suitable for use in the shack and would sit nicely on top of a FT817/8 etc, the other is more suitable for use in the field with its top mounting controls and very small size. Both of these ATU work the same and are designed to work from 3.5Mhz to 30Mhz (Some customers have found that they work well on 6m too) The Transmatch is easy to use, much easier than many manual ATU’s. While tuning I recommend reducing powder if you can (be nice to other Hams). A watt or two will be plenty. If using a coax fed antenna make sure that you select ‘Un-Bal’ on the rear panel switch, if using a balanced feedline then set the switch to ‘Bal’.
With the ATU fitted between the radio and the antenna first set the controls to the 12 o’clock position. Flick the front switch to OPER and set the radio to the required operating frequency, adjust the two ATU controls for max noise in the receive, this will normally put you in the right ball park anyway, now switch the ATU switched to ‘Tune’, give a steady RF carrier. The LED will light (unless already at the best spot!) Adjust the two controls to find the point where the LED goes out (or becomes very dim). Take care as the tuning will be sharp. This is the sweet spot and you will find that you have a good usable match to the antenna. Flick the switch back to operate and you’re done. If you have a SWR indicator on the radio you may be able to tease the SWR down further now by making very small adjustments to the controls. The LED indicator will normally go out around a SWR of 1.5:1, this is a perfectly usable match and further improvement will have little advantage. Many of us over worry about wringing the last fraction of match from an ATU, When the light goes out your good to go. After a short while you will begin to trust the LED indicator and stop looking at the Radios SWR meter.
Trouble shooting
If the LED is very dim at all settings of the controls you may have the sensitivity trimmer set to low, the LED gets its power via a voltage produced when there is a mismatch, All LEDs need a minimum voltage to operate, there is a little trimer on the main PCB that allows you to adjust the sensitivity (and brightness) of the LED, I like it very bright so tend to turn the sensitivity to max (well just under it really), with a low power carrier applied adjust the trimer to give a bright LED .
You just can’t tune an antenna on a certain band?
ATU’s have their limits, sometimes they just can’t give you a match. Try the antenna on a different band to start with, if you can match it then you most likely have a difficult length antenna, sometimes if the antenna can present a very high impedance (or very low) at a certain frequency, try adding a few feet to the length (or shorten if you don’t have the room) and test again, just a few feet can make a massive difference. Also the feed cable (Coax) length can cause problems, if you can try a shorter or longer length just a few feet can make all the difference. If you have a balanced feeder you will need to provide an adapter to allow this to be connected to the ATU, make sure that you flick the switch on the rear to BAL in this case (Normally should be set to Un-Bal for coax feeds).
I hope that the MTM-ATU gives you good service. 73 Paul M0BMN