Hello All,

I need to use MAR-6+ mini-circuit in my design (for first time!) but not sure how to connect its very small leads as each of these has length just about few millimeters and, hence, does not seem suitable for ordinary soldering.

So, my question is: whether mini-circuits like MAR-6+ are suitable for soldering or their leads has to be connected in some other way?

 

Ah, early surface mount. I used to make 2.135Ghz to 70Mhz down covertors from kits, the transistor (I know, device, since it is more than that) is meant to merge smoothly with a matched impedance line on a PCB. The units I used were good for LNAs and oscillators, in the case of the down convertor the local oscillator was tuned by cutting a non terminated line to a specific length. If you went too far you had to solder a wire on and start cutting it down.

Basically think something like a 50Ω strip with a ground plane on the PCB board. Where you wanted the transistor you drilled a hole, and soldered it in. From there it is just a matter of biasing the sucker up. Never designed well with them though, kept making better oscillators than amplifiers.

 

Hello,

Here is an example on how to contruct an amplifier with the MAR6+.
http://www.g4aym.org.uk/project1/page1.htm

You can take the part you need.

Greetings,
Bertus

 

Hello,

Here is an example on how to contruct an amplifier with the MAR6+.
http://www.g4aym.org.uk/project1/page1.htm

You can take the part you need.

Greetings,
Bertus

Hi Bertus,

This's very helpful link indeed. Many thanks.

 

Ah, early surface mount. I used to make 2.135Ghz to 70Mhz down covertors from kits, the transistor (I know, device, since it is more than that) is meant to merge smoothly with a matched impedance line on a PCB. The units I used were good for LNAs and oscillators, in the case of the down convertor the local oscillator was tuned by cutting a non terminated line to a specific length. If you went too far you had to solder a wire on and start cutting it down.

Basically think something like a 50Ω strip with a ground plane on the PCB board. Where you wanted the transistor you drilled a hole, and soldered it in. From there it is just a matter of biasing the sucker up. Never designed well with them though, kept making better oscillators than amplifiers.

Thank you

 

Well, I have managed to solder the leads of MAR-6+ using 8W soldering iron and it works now. One stage amplifier gives more than 20dB gain as shown on picture attached - blue and red traces are time averaged input and output respectively. After some filtering I hope to get rid of unwanted components in spectrum in order to leave the only useful signal, which is at 8 MHz (marked by dashed line on the picture).
So MAR-6+ does its job quite well!

 

Hello Vladimir,

What is the range you are interested round this 8 Mhz?
Is it a some khz wide or Mhz?

Here is a link with some RF tools:
http://www1.sphere.ne.jp/i-lab/ilab/index_e.htm

Press the button "TOOLS" on the left to enter the calculator menu.
There you will also find a bandpass filter calculator.

Greetings,
Bertus

 

Since I make such bad amps (or good oscillators) I would be interested in seeing it.

 

Hello Bill,

Here is a schematic with the MAR6 from ON6MU:
http://users.belgacom.net/hamradio/schemas/preamp_HF_VHF_UHF_SHF_wideband_MAR6.htm

It also makes notes on the usable frequency range.

Greetings,
Bertus

 

Hello Vladimir,

What is the range you are interested round this 8 Mhz?
Is it a some khz wide or Mhz?

Here is a link with some RF tools:
http://www1.sphere.ne.jp/i-lab/ilab/index_e.htm

Press the button "TOOLS" on the left to enter the calculator menu.
There you will also find a bandpass filter calculator.

Greetings,
Bertus

Hi Bertus,

Thanks for advice. I will try high-pass filter (which attenuates components with frequencies below 7.5 MHz) shown on the picture attached.

 

Since I make such bad amps (or good oscillators) I would be interested in seeing it.

Hi Bill,

The schematics which I use is taken from MAR-6+ datasheet (pdf file attached) and is shown on the picture attached as well. I just have used for the frequency range of my interest Cblock=10nF, Rbias=220 Ohms, Vcc = 7 V, RFC (which is optional) is not used, and Cbypass=130pF is used.