Analogue Wireless UHF Microphone System

Author and Photos: Peter Kaminski

686 RX2

The TXS-600 series from IMG STAGELINE is distributed by MONACOR INTERNATIONAL and includes various transmitters and receivers operating in the UHF frequency range, e.g. single-channel desktop receiver TXS-606, 2-channel 19" rack-mounted receiver TXS-626, 4-channel 19" rack-mounted receiver TXS-646 and 8-channel 19" rack-mounted receiver TXS-686. Transmitters are also available, e.g. gooseneck desktop microphone transmitter TXS-606DT, pocket transmitter TXS-606HSE, microphone transmitter TXS-606LT with lavalier microphone and hand-held transmitter TXS-606HT.

There are sets available which are also named TXS-600. However, it is worth mentioning that these sets only offer partial compatibility and may even operate in a different frequency range. The TXS-600 series shown here uses the frequency range 672.000-696.976MHz. Each device features 1,000 selectable channels which are devided into 10 groups with 100 channels each.

The frequency range 672.000-696.975MHz is not part of the licence-free UHF frequency range and requires a licence. Thus, it is more suitable for professional users. For information on the registration in your country, please contact your local authority.


686 RX1

From the wide range of receivers available, we would like to show you the top model TXS-686 which features eight receiver channels and is accommodated in a 19" housing with 2 RS. The receiver is equipped with a diversity receiver and thus provided with two antenna jacks (BNC). The device is supplied with respective antennas.

686 RX4

Eight outputs of the channels (balanced XLR jacks) are located on the rear panel.  The RF squelch, i.e. the threshold value set for muting the channels can be adjusted individually via a little trimmer. The individual outputs provide a microphone level with an impedance of 25mV and 600 ohms. Furthermore, there is a mix out (6.3 mm stereo jack) for monitoring purposes with a line level of 350mV. An external plug-in PSU supplies the power.  The audio frequency range for the transmission path is stated as 30Hz-18kHz.

686 RX3

Each receiver features an individual section for setting parameters or displays for indicating the operating status. For this purpose, LEDs are located just above the backlit LCD. They indicate active antenna, audio signal level and infrared synchronisation. On the right side, there are 3 momentary push-buttons for selecting UP, DOWN and SET. The SET button allows you to select group, channel or output level and change them using the buttons UP and DOWN. Once you have finished adjusting group, channel and volume, press the SET button again to change from setting mode to standard operating mode. And those are all the settings you need to adjust. The multilingual instruction manual shows a table at the end of it listing the channel frequencies of each group.

Before we go into detail on the individual transmitters, please note that the transmitters are synchronised with the receiver or receiver channel and its selected frequency via infrared, i.e. no need to set the frequencies at the transmitter. To link the frequency to the receiver channel, press the ACT button at the respective receiver channel and it will then be passed on to the transmitter. For transmission, the receiver must be within reach of the infrared transmitter (1.5 metres or less).


606DT Schwanenhals1

Both the 8-channel receiver and the desktop transmitter TXS-606DT with gooseneck microphone were shown at the prolight+sound 2016. The desktop microphone features a base with integrated electronics (120x65x187mm, approx. 600g), a pluggable gooseneck microphone with latching device and a windshield.

606DT Schwanenhals2

The base features an integrated LED at the bottom for indicating the mute status as well as a display giving information on group, channel and battery status. The desktop transmitter is operated via two batteries AA size which allow an operating time of more than eight hours. Pressing the button on the top of the base allows you to switch between muting the audio signal and audio transmission. To switch off the transmitter, press the button longer. To switch it back on, briefly press the button again.

606DT Schwanenhals3

You can set the microphone sensitivity on the rear panel of the desktop transmitter and use a sliding switch to select the transmitting power between 2.5mW and 25mW EIRP.


606HSE Taschensender1

The LCD on the front panel of the pocket transmitter TXS-606HSE (61x106x27mm, 96g) also shows the frequency group, channel and battery status. For operation, this device also uses two batteries AA size which guarantee an operating time of more than eight hours, too. The TXS-606HSE features a transmitting power of 10 mW and a rigidly attached antenna.

606HSE Taschensender2

A mini XLR jack (unbalanced connection) is located at the top of the device (see photo above) for connecting an electret microphone, e.g. headset microphone HSE-80 from IMG STAGELINE. A supply voltage for electret microphones is available at the jack. The transmitter can be switched on (ON), off (OFF) or be switched to standby (STDBY) via a 3-step sliding switch.

606HSE Taschensender3

A metal belt clip is attached to the back of the device. The GAIN trimmer with protective cover allows you to adjust the input sensitivity of the microphone.


606HT Handmikro1

The TXS-600 series also offers hand-held microphone transmitter TXS-606HT (diameter: 51mm, length: 265mm, weight: 312g). It features a built-in dynamic microphone cartridge of cardioid characteristic which cannot be replaced. Unlike other transmitters, this one allows you to select the frequency directly via three buttons after unscrewing the cover. The microphone sensitivity can also be adjusted in 4 steps (0, -10, -20, -30dB) via the UP and DOWN buttons. The battery status is, again, indicated via a display.

606HT Handmikro3

A small sliding switch at the bottom of the handle allows you to change the transmitting power between 2.5mW and 25mw EIRP. For practical reasons, this switch is only accessible when the cover of the hand-held device has been unscrewed. The large sliding switch also allows you to switch-off the hand-held microphone when the cover is screwed on.


The TXS-600 system from IMG STAGELINE is intentionally not equipped with extensive adjusting facilities which results in a very easy-to-use device. Thus, it is very well-suited for users without expert audio knowledge who want to operate a wireless microphone system. IMG STAGELINE has successfully managed this. It is almost impossible to facilitate operation even more without limiting basic functions, too. Despite an easy operation, the system clearly indicates the operating status of every component at all times.

The instruction manuals of the components do not provide any information on intermodulation-free frequency groups. However, the combination with eight groups/channels 01|00, 03|00, 05|00, 07|00, 02|57, 04|00, 06|00 and 08|00 allows an intermodulation-free operation of eight channels.

The system features a wide operating range and can even compete with far more expensive systems. It also provides an impressive sound quality and S/N ratio.

The hand-held microphone TXS-606HT is susceptible to pop noises. Thus, the required distance should be kept and an optional windshield is recommended. This device also provides a high-quality sound. When using the hand-held device as a desktop microphone, I would recommend to slightly boost the high frequencies to deliver a sound with an increased presence and to attenuate the bass frequencies to achieve a more balanced sound. The TXS-606HT is sufficiently protected against handling noise. For the 8-channel receiver, I would have maybe liked an extra headphone output for monitoring purposes but at least it is equipped with a mix line level output.


The easy operation and, without a doubt, the attractive price of the components make the TXS-600 series a very interesting system. The desktop receiver TXS-606 is available for about 209 Euros, the 2-channel rack-mounted receiver TXS-626 for about 285 Euros, the 4-channel rack-mounted receiver TXS-646 for 459 Euros and the 8-channel rack-mounted receiver TXS-686 is available for 929 Euros. The gooseneck desktop microphone transmitter TXS-606DT can be yours for about 180 Euros. The pocket transmitter TXS-606HSE as well as the transmitter TXS-606LT with lavalier microphone and the hand-held transmitter TXS-606HT are all available for 115 Euros. Therefore, the price-performance ratio can be considered exceptional with a good workmanship of the mechanical components.

An easy operation, an attractive price and an extensive range of features make the TXS-600 series perfect for fixed installations. Due to the highly reliable gooseneck desktop microphone transmitters, the TXS-600 system may also be interesting for use as compact conference systems, e.g. in hotels or companies. You do not have to be an audio expert to operate this system, it is sufficient to have some basic technical knowledge.