Steamed Snapper, Asian Style

This is no Pasta Pete recipe and I am not as famous as the man himself, but, I do cook, can cook and now and again knock one out of the park.

Tonight’s dinner steamed whole snapper with stir fried vege and noodles. The fish is stuffed with chili, ginger, garlic and spring onion, and topped with the same and a good splash of soy sauce and sesame oil. Steam in a bamboo basket until cooked.

The vege is just anything you like, I did red capsicum, zucchini, beans, snow peas, carrot and mushrooms, in a little Yaki Udon sauce and some slurpy Korean noodles.

If the proof is in the eating, all said and done, there was nothing left on the plate.


Fish all prepped and ready for steaming.

The final dish as served to the table. 
Facebooktwitterredditpinterestlinkedin

4 Band Bandpass Filter Board

The relays are double pole double throw in a standard 18x9mm package size. The transistors are anything you have in CBE footprint, I used 2n3904 and the resistor is there for current limiting, just pick a typical value, i think i used 4.8K. The trimmer caps I use are 3 leg 100pf max value to tune and align each filter.

SMA edge connectors bring RF in on the left side of the board. By default all relays are in the OFF position and no RF can pass through. The 6 pin header brings control signals and power to the board. To turn a relay on, a 5v control control signal is placed on one of the first 4 pins to turn 1 pair of relays on. The last 2 pins are ground and VCC of the relays you used.

 

Aligning each filter can be a bit tricky, it is best to use a spectrum analyzer and tracking generator if you have one, or a noise source and spectrum analyzer or even in a pinch if you slow down the seconds/division on the oscilloscope so you can see the filter shape. The reason being, if your filters are not quite tuned right, you will end up with 2 peaks and some attenuation in the bandpass you just do not want.

The filters themselves are Double Tuned circuits. To design the values needed for each band I used some software called DTC.exe which can be found on a CD in the book Experimental Methods In RF Design. I have linked it here for download, but I am not sure if I am allowed to and i will pull it down if asked by the authors: DTC DOWNLOAD

The gerber files for the board can be downloaded from here:

Here is a schematic of the filters with values for 80, 40, 20 and 15m.


Facebooktwitterredditpinterestlinkedin

4 Band Lowpass Filter Board

Board Design 

Ok, in the spirit of sharing and making things easy for people, I am going to start releasing some gerbers for the various boards I have designed for my various projects, that work HAHAHA, because, yes, not everything i do works.

I am not into this for making money, I do everything that i do simply for the love of it and for the learning experience. So selling boards and things is not high on my agenda. And besides, you can get 10 boards made and send to you from JLCpcb in China for not much more than it would cost me to send you one from Australia.


First cab off the ranks 7th order low pass filter boards. So you will notice there are no part values on the boards. Why? Well because i do not know what bands you might like to build for. The relays are double pole double throw in a standard 18x9mm package size. The transistors are anything you have in CBE footprint, I used 2n3904 and the resistor is there for current limiting, just pick a typical value, i think i used 4.8K.

SMA edge connectors bring RF in on the left side of the board. By default all relays are in the OFF position and no RF can pass through. The 6 pin header brings control signals and power to the board. To turn a relay on, a 5v control control signal is placed on one of the first 4 pins to turn 1 pair of relays on. The last 2 pins are ground and VCC of the relays you used.

For designing the filters I use an online calculator like this one at Calculators Edge: http://www.calculatoredge.com/electronics/bw%20pi%20low%20pass.htm Or a software tool like Elsie.

Lowpass Filter Board

Gerber Files can be downloaded from HERE:  http://robs-blog.net/Files/LowPass_Filter.zip


Facebooktwitterredditpinterestlinkedin