FAQ

Bank details


Difference between MKU 10 G3 and MKU 10 G4

The main difference between the MKU 10 G3 and the MKU 10 G4 is the oscillator path.
The MKU 10 G3 works with an multiplied crystal oscillator, the MKU 10 G4 works with a PLL oscillator.
In the MKU 10 G3 the frequency stability is achieved with a crystal oscillator with crystal heater.
In the MKU 10 G4 we are using a very good TCXO to get a good frequency stability.
Because of the PLL design the MKU 10 G4 can be produced faster and we are more flexible with the IF frequencies.

Using the ICOM IC-7300 with Kuhne’s Transverters

Please click here for a modification instruction for the IC-7300 to provide a low power level transverter interface to be compatible with Kuhne’s transverters.

RF power of Bias-Tees

Our bias-tees KU BT 3001 N and KU BT 271 N are intended for voltage supply of Low Noise Amplifiers (LNA) and Low Noise Converters (LNC), but not for Power Amplifiers (PA). The KU BT 271 N is specified for the following maximum RF power: 20 W @ 144 MHz, 5 W @ 435 MHz and 1 W @ 2000 MHz. We expect similar values for the KU BT 3001 but this is not specified. If there’s only one frequency band required we can probably offer you a special version with more RF power. Please specify the required power and the frequency.

Frequency allocations for amateur radio activities

Frequency allocations for amateur radio activities (SSB / CW) in Europe (defined by the IARU).

- Specifications subject to change without notice -
 
carrier band frequency
23 cm  1296.0 ... 1297.0 MHz
13 cm 2320.0 ... 2321.0 MHz
9 cm  3400.0 ... 3401.0 MHz
6 cm  5760.0 ... 5761.0 MHz
3 cm 10368.0 ... 10369.0 MHz
1,4 cm  24048.0 ... 24049.0 MHz
0,8 cm  47088.0 ... 47089.0 MHz
4 mm 76032.0 ... 76033.0 MHz
2,4 mm 122250.0 ... 122251.0 MHz
2,2 mm 134928.0 ... 134930.0 MHz
1,2 mm 241920.0 ... 241921.0 MHz















 

24 V fans can be operated with 28 V

We checked our 24 V fans with a supply voltage of 28 V over a period of time and so far we didn’t notice any problems.

External filter for MKU 13 G3 28 required

Our transverter module MKU 13 G3 28 requires an external filter for image rejection. You can find filters here.

The non-harmonics of the MKU 13 G3 28 are specified with typ. -30 dBc, so the specification of the filter depends on your own requirements: if you need -60 dBc your filter must provide a cutting depth of 30 dB etc.

MKU 144 G2 with external oscillator:

Modification instruction please click here 

Silver conductive

Unfortunately we cannot offer conductive silver adhesive, please check out the web for CircuitWorks CW 2400 which is provided by many suppliers (Bürklin, Conrad, Voelkner, Farnell, Mouser, etc.).

Another (but expensive!) solution is the material EPO-TEK H20E which is supplied by the following company: www.jpkummer.com

When do I need an isolator for my power amplifier?

An isolator protects the power amplifier in case of bad antenna matching as it prevents reflected RF to go back into the final stage. So if you have a good antenna situation where the VSWR is always fine, you really won’t need an isolator. But if there is the chance that the antenna might be forgotten or damaged it is really worthwhile to protect the power amplifier. Generally the VSWR of load is specified with 1.8:1 for all of our power amplifiers.

Sequence Controller

We strongly recommend the use of a sequence controller for your amateur radio system. Many coaxial relays have too low isolation between the ports during the changeover. If the power amplifier (in a transmit-receive system) is switched too early, this may lead to damage or destruction of the input transistor in the LNA or converter. With a sequence controller this trouble can be avoided. The sequence controller provides a control signal for the coaxial relay and it switches the voltage supply for the power amplifier. There is a time delay between the two signals to guarantee safe switching.

Our sequence controllers are intended to control a power amplifier and an antenna relay - not to control a transverter module. Your transceiver must provide a ‘PTT to GND’ signal to switch the transverter module into transmitting mode. If you don’t use a power amplifier it is not necessary to use a sequence controller.

No bi-directional functionality / no built-in coaxial relays

Our modules are not designed for bi-directional applications and don’t include any coaxial relays. The switching between transmitting and receiving must be done externally by the customer – there’s no RF switching implemented!

Kenwood TS-2000

We do not recommend the TS-2000 for transverter operations because this transceiver produces power spikes of more than 60 W even when it is run with low power!

Monitor Output

Most of our power amplifiers include a built-in directional coupler for detection of the forward output power. So the output power can be observed by a simple DC voltage - it is proportional to the RF power, but not calibrated and no linear function.

Output power: COFDM versus CW

Generally the output power of our power amplifiers is specified for a single carrier CW signal. If you'd like to use them for COFDM / digital modulated signals you can expect an output power of about 10 ... 20 % of the CW power. This depends on the type of modulation you want to use and the required signal quality and specifications.

How do I have to connect my amplifier which has the pins "+12V" and "D+"?

The terminal "D+" must be permanently connected to +12 V (in German: "Dauerspannung" = permanent voltage). This is to produce a permanent negative gate voltage for the MOSFET.

In TX case you only add 12 V to the +TX port. The D+ voltage should remain in TX and RX case.

Setup Example of a 10 GHz Transverter by DC0DA

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Information about 10 MHz reference input of DB6NT transverters

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Modification of the transvertermodul MKU 144 G2 to external oscillator

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RX-TX switching of DB6NT transverters

To switch a DB6NT microwave transverter from receive (RX) to transmit (TX), there are two possibilities. 
The first: switch the port "PTT" of the transverter to ground for TX. 
The second: supply +3 … 12 V DC to the core (center conductor) of the IF cable for TX. 
This (second) method saves an additional PTT cable between transverter and transceiver.

A suitable control circuit is already included in the transceivers YAESU FT-290R (old model) and ICOM IC-402. They provide +12 V DC on the coaxial output connector (core) at TX. 

The YAESU FT-290RII (new model) does not provide this function, but it can be modified. The modification is described on G4DDK's homepage: www.g4ddk.com/Techstuff

Modification of the ICOM IC-202

ATTENTION!The ICOM IC-202 provides +12 V at RX! So when you connect a DB6NT transverter to a IC-202, then the transverter will switch to TX.Therefore, a small modification is necessary (see picture below). With this modification the IC-202 will provide +12 V at TX.



Modification of the YAESU FT-817


The YAESU FT-817 must also be modified for transverter operation. Peter Vogl, DL1RQ, has written a small tutorial how to do this modification: www.bergtag.de/technik_18.html 

A further description for the YAESU FT-817 is written by Pedro M.J. Wyns, ON7WP. 

Everybody uses DB6NT transverters above 1000 MHz. These babies need a positive voltage on the coax middle pin in order to switch into TX mode. As a lot of microwavers have FT817 radios so it would be nice to have a "lazyham interface" for these fine little Yaesu radios.

The pictures are self explaining. Cut the wire going towards the SO239 antenna connector on the rear. Insert instead of the wire a parallel configuration of 1 and 10 nanofarad capacitors. Connect a 1200 ohm resistor to the center pin of the connector, the other end to a feedtrough 1 nanofarad capacitor (or something alike) mounted/soldered to ground and connect the other side of this feedtrough with a (red) wire to the solder pad on the PA module.

Pedro M.J. Wyns ON7WP (AA9HX when abroad)

     

Modification of the RX-TX switching in the YAESU FT-817 (Photos by ON7WP)

Thanks to Pedro, ON7WP, for his description and the photos!

Alteration YAESU FT817 for RX-TX switching DL6NCI

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Modification for separated IF

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Modification - Low Power Interface

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