swr meter

my friend  Mr. Rezaee  vswr  meter

dds amplifier

/iranian-contest/

http://www.dxcoffee.com/eng/2016/iranian-contest/

AD9850 DDS based Antenna Tuner Adjustment Aid

ARDUINO project

AD9850 DDS based Antenna Tuner Adjustment Aid

If you use a manual antenna tuner to match your transmitter to the antenna, not causing QRM while your making the adjustments can be an issue.. This project eliminates that problem by using a very low level signal and a very sensitive SWR bridge.

An inexpensive Arduino board is use to control a AD9850 DDS module and LCD display, while a handful of discrete parts comprise the SWR bridge. A simple LED is used as the match indicator.

Operation:

It is very simple.

A preprogrammed frequency for each of the HF bands, 160 to 10 meters is selected by repetitively pushing the [ CHANGE BAND ] switch. I programmed in the various QRP calling frequencies in the CW segment of each band. You can of course change that in the Sketch by changing the frequency (freq) in the band look up table.

The operating frequency can be changed using a rotary encode with Gray code output. If the frequency changes in X2 steps, you have an encoder with quadature output.

The default tuning rate is 10 kHz, which allows for quickly moving the frequency to another part of the band. The tuning rate can be changed by pushing the [ CHANGE RATE] button. 10 Hz, 100 Hz, 1 kHz and 10 kHz rates can be selected. The active decade for tuning is indicated by the cursor underscore of the selected decade.

Note that tuning limits are enabled so you can't tune outside of the selected Ham band.

Once the desired band and frequency is selected, the [ TRANSMIT ] toggle switch is used to turn the DDS signal on and off. .

When the [ TRANSMIT ] switch is closed, the DDS is loaded with the frequency data, a 600 Hz sidetone is generated and Pin 8 is set HIGH, which can be used to control a power amplifier or switch over relay. When the [ TRANSMIT ] switch is open, it loads 0 Hz into the DDS chip, effectively turning it off. You don't want to leave it on or there will be a birdie at that frequency in your receiver.

You will of course need a coax switch ( or relay) to switch the antenna tuner between this device and your rig.

With the tuning aid connected to your tuner, adjust the tuner to make the indicator LED go out or to dim as much as possible.

Theory of operation:

The SWR bridge and indicator:

The SWR bridge is a Whetstone configuration, with the antenna in the unknown leg of the bridge. If the resistance of each leg is equal, there is no voltage difference between the center of the two legs, which indicates a match. I used 51 ohm resistors in the bridge as their close enough to 50 ohms, but if you do want an exact 50 ohm match, use 100 ohm resistors in parallel instead.

The bridge is driven by the square wave output of the AD9850, through a simple L/C low pass filter to remove most of the harmonics. With out this filter, harmonic from the square wave drive will reflect back and keep the LED from going completely out or at least get very dim. The filter starts to roll off at about 2 MHz so there is still enough harmonic energy when operating below 30 meters and the best you can do is make the LED very dim. You can still achive a 1:1 match without using the low pass filter, but the dip is much harder to see.

If the resistance of the unknown leg is not equal to the value of the other three resistors in the bridge, there is a voltage difference between the centers of each leg. This voltage is coupled to a high gain darlington amplifier using a step up transformer. R1 and R2 supply just enough voltage bias to the base of Q1 to improve the sensitivity without actually turning it on. A LED in series with Q2 which provides a visual indication of the amount of current flowing into the amplifier. The greater the imbalance of the bridge, the greater the voltage inputted to the amplifier and the greater the current in the collector path. The is only one potential problem with this method. If you live near a AM broadcast station you might pick up enough signal to keep the LED on all the time as you won't be able to balance the bridge at that frequency.

Construction:

I intially used a UNO R3 board for develpoment, but used a NANO board for the final assembly. The schematic show wiring for the NANO board. Because the AD9850 and the LED back lighting of the display use a fair amount of current, a seperate 5V regulator is used to power these devices, rather then using the 5V regulator on the NANO board, as it would likely get very hot.

There are two types of AD9850 DDS modules available from China. I used the one with the two rows of 20 header pins and looks like a large DIP IC. If you use the other flavor, just follow the hook up diagram to connect to the required pins. These DDS modules are running about $10 at the time of this writing. Pretty amazing since the AD9850 chip costs $21 if you bought it all by it's self.

The LCD is a common 2 line, 16 character display. The ones with blue back lighting are very common and inexpensive. These run about $3.

All three of these major components can be obtained inexpensively direct for China buying with ebay. It just takes a few weeks to get them. If your in more of a rush, banggood.com can ship these from a US warehouse for a small price premium.

The rest of the discrete parts needed to build the SWR bridge and indicator can be obtained for the usual sources like Mouser or Jamesco. The MSP5179 transistors have a 1 GHz hft, so they still have decent gain at 28 MHz. You could sub the more common 2N3904's but it won't be as sensitive on the higher bands or may not work at all. If the LED does not light or is very dim at the higher frequencies, you don't have enough gain.

Since most of the componets are modules, I buit the project on a piece of FR4 pref board, using SIP sockets for the modules to plug into. The SIP sockets come in 40 pin strips. To cut them down to size, remove the pin one location past the number of pins you need and cut that slot with an hobby knife of razor saw. I use #28 heat stripable magnet wire to make all the interconnections. That way I don't need to strip insulated wire and makes for a neat looking wiring job.

The SWR bridge and amplifier could have been wired up right on the perf board, but I built it on a small scrap of copper clad board, dead bug style, which is a bit quicker and easier way to build it.

For final packaging, I recycled an old Radio Shack enclosure. Since the front panel of this box already had a number of holes in it (all in the wrong places, except for the display window, which was cut for a smaller display) I had to cover the old holes up somehow. I did this by simply putting down some double sided tape on the panel and then laid down a piece of black contruction paper and trimmed it to fit. This is then covered with a thin piece of clear Polycarbonate, which is easy to work with.

Programming the Arduino and the program "Sketch":

Hopefully your already familiar with the Arduino. If not a simple web search will come up with linksto the official Arduino web site with all the info you need.

The Sketch which you need is located in this zip file: Arduino_9850_sketch.zip

Once the Sketch has been downloaded into the Arduino board and everything is wired up, you will have to make one adjustment on the DDS module board. With the "unknown" leg of the bridge open, adjust the little trimmer resistor on the 9850 module until the SWR indicator LED comes on brightly. This trimmer sets the duty cycle of the square wave output and you want it more or less centered at 50%, but without a 'Scope just set it in about the middle of the adjustment range which makes the SWR LED stay on.

Parting thoughts:

This is my first Arduino "Sketch" and I'm pretty amazed I was able get it to work. I did take some late nights just to figure out how to do some simple things. I normally program directly in assembly which makes a whole lot more sense to me and is vasty more memory efficient and faster.

Although I designed this for the SWR bridge application, it can also be used as a signal generator, a transmitter VFO or even the VFO for a transceiver, although some modifications to the Sketch will be required for other applications.

For use as a signal generator with full tuning range, comment out the band limit tests in the DDSincerment() and DDSdecerment() routines and enable the max freq and min freq limits instead.

For a transceiver, you can add or subtract an offset to the base frequency before loading the DDS chip.

Anyway, I hope someone finds this project useful.

73, Steve KD1JV

hf reciver

مطلب فوق را جناب مهندس رسولي ارائه كردندو ازين بابت بسيار سپاسگذارم

contest

مسابقه دهه فجر

wide band irf hf amplifier

با سلام

 دوست عزيزم  مهندس دل قوي توانستند با ترانزيستور هاي سويچ خانواده IRF  تقويت باند پهن اچ اف بسازند

 طرح اوليه متعلق به مهندس عاملي است كه با تغييراتي توسط مهندس دل قوي فعال شده و خروجي راديو گيرنده مولتي اس اس بي را 30-40 وات تقويت مي نمايد

اصل طرح و نمونه برد مهندس عاملي

آنتن ميله اي تمام باند اچ اف

با سلام مدار جالبي براي تمام باند اچ اف با 15 متر سيم

طرح توسط مهندس حميد مثيمي  اراعه شده است

ادرس اصل طرح و توضيحاتش:

http://gerritvinke.wix.com/hamradio-pa3dwc#!broadband-antenna/c158s

كاربرد بالون يك به يك

با سلام  مطلب جالبي راجع به كاربرد بالون در انتن اچ اف

مدارات كنترل صدا براي مدولاسيون سينگل سايد باند

با سلام

چند نفر از دوستان مدار كنترل سطح خودكار صداي ميكروفون براي مدولاسيون SSB ساخته اند كه بسيار خوب عمل كرده و صدارا كمپرس نموده و در ارسال سايد باند ثبات بسيار جالبي ايجااد مي كند

مدار اول متعلق به مهندس كياني EP5MKN مي باشد

مدار بعدي ساخته مهندس ظهوريان است

EP2HZM

تقويت كننده باند پهن با ترانزيستور اكسيد فلزي و 70 وات خروجي 2

با سلام در ادامه مطلب مهندس سهرابي   مدار تقويت كننده ايشون تقديم مي شود

تقويت كننده باند پهن با ترانزيستور اكسيد فلزي و 70 وات خروجي

با سلام

يكي از دوستان و علاقمندان مدارات الكترونيك و از مشتريان پروپاقرص  مهندس عاملي جناب مهندس محمد سهرابي چند طرح ايشون رو ساخته و تكميل كرده اند

1- فرستنده گيرنده  27 مگا با توان ده وات و سوپر هتروداين كريستالي

وبلاگ جناب مهندس رئیس دانا

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جناب مهندس رئیس دانا بنیانگذار مجلات و نشریات علم الکترونیک و مخابرات و  رادیو تلویزیون ایران  وبلاگی دارند که توسط ایشان مطالب بسیار وزین و با ارزشی منتشر می گردد

سعی من استفاده از مطالب گهربار و جالب ایشان است و دوستان و علاقمندان را نیز توصیه به بررسی  ان می نمایم

با آرزوی توفیق روز افزون  و موفقیت بیش از پیش ایشان

etesalkootah.blog.ir

آنتن تيونر براي QRP تا 30 وات

با سلام  تازه ترين طرح  مدار تطبيق امپدانس انتن از مهندس قنبري

ليست دارندگان پروانه راديو آماتوري

تراپ يا فيلتر هاي باند جهت انتن هاي چند باند

با سلام

يكي از دوستان راديو آماتور جناب مهندس حسن ظهوريان EP3HZM  انتن دايپل چند باند ساخته اند كه منبع بررسي و تحقيقات و ساخت انراهم ذكر نموده اند

ضمن تشكر و نمايش انتن طراحي ايشان توضيحات نيز ضميمه مي شود

نحوه تنظيم و ساخت مدار تست تراپ ها

روش ديگر ساخت تراپ با استفاده از فيبر مدار چاپي دورو بجاي خازن

مدار تست تراپ

آزمون راديو آماتوري

با سلام و تبريك ايام

دوستان و علاقمندان به راديو آماتوري

لطفا نسبت به ارسال درخواست شركت در ازمون راديو اماتوري اقدام فرمائيد

در سايت هاي زير فرم ثبت نام اورده شده و در صورت رسيدن به حد نصاب ازمون برگزار خواهد شد

لطفا به اطلاع دوستان خود هم برسانيد تا فرصت باقي است نسبت به ارسال درخواست شركت در ازمون راديو اماتوري اقدام فرمايند

www.ephamshop.com

www.ephamradio.com

ardino2

http://www.phonestack.com/farhan/bitx.html

ardino radio

با سلام  و  تسليت ايام

استفاده از اردينو براي راديو

آرشيو مجلات

سلام دوست عزیزم مهندس کشاورز  مجلات الکترونیک و رادیو تلویزیون رو آرشیو می نمایند لذا دوستان علاقمند ضمن تماس با ایشان نسخه مجله خودرا امانت بایشان داده تا پس از اسکن عودت فرمایند   ۶۶۹۰۷۴۵۹

دارندگان پروانه راديو آماتوري

تماس راديوئي

با سلام و آرزوي سلامتي همه عزيزان

امروز بعد از 45 سال اولين تماس با كالساين رسمي خودم EP5ABD  را گرفتم و  تونستم با بقيه دوستان در شيراز تهران كرج تبريز و مشهد تماس بگيرم

به خودم و بچه هاي گروه و همه علاقمندان راديو تبريك مي گويم.

جادارد از مسئولين محترم رگولاتوري خصوصا جناب ميري و  ساير همكارانشان تشكر ويژه داشته باشم

از جمله تست هاي جالب تماس در مود AM  و   FM   بود كه صدا  خيلي جالب و قشنگ بود

طبق پيش بيني ها ما چند ساعت بيشتر انتشار محلي مناسب نداشتيم  لذا  اين چند ساعت را با تست و كيفيت سنجي و انواع انتشار گذرانديم

سعي مي كنم در مرحله بعد در صورت امكان قبلا اعلام كنم تا علاقمندان بتوانند با حضور روي فر كانس با گروه تماس گرفته و يا صداي مارا بشنوند.

با آرزوي بيشتر و بهتر شدن و فعاليت روز افزون اعضاء و علاقمندان ايراني در سراسر جهان

EP5ABD

REZA

new lisenced r.a. callsign

EP3PTT

dds

با سلام

با کمک  دوست عزیزم  آقای سجاد  از دزفول  توانستم  یک دستگاه  نوسانساز   دیجتال - آنالوگ  با ای سی 9850  ساخته و  از 100کیلو تا 40 مگا(39999999هرتز) را راه اندازی نمایم

نقشه سیم کشی و نماهایی از دستگاه ساخته شده جهت اطلاع دوستان ارسال می گردد

سوار بر امواج رادیو .

 http://www.jadidonline.com/images/stories/flash_multimedia/iran_radio_amateurs_56/radio_low.html

http://www.jadidonline.com/story/28052015/bhr/iran_radio_amateurs 

گواهينامه راديو آماتوري

با سلام

باطلاع جميع دوستان  و علاقمندان راديو آماتوري كه در آزمون سال گذشته قبول شده اند مي رساند  :

جهت در يافت گواهينامه خود و تكميل و ارسال فرم درخواست پروانه به رگولاتوري مناطق  خود مراجعه فرمايند.

مثلا در اداره رگولاتوري منطقه اصفهان بيش از سي 30  كارت  گواهينامه حاضر و منتظر حضور داوطلب جهت در يافت آن مي باشد.

لطفا سريعا با مراكز منطقه اي خود تماس  حاصل نموده يا مراجعه نماييد

آزمون رادیو اماتوری

با سلام

سازمان تنظیم مقررات  یا همان  رگولاتوری  قصد برگزاری آزمون رادیو آماتوری در سال جاری را دارد.

از علاقمندان درخواست می شود با تلفنهای سازمان یا سایت  www.cra.ir تماس گرفته و ثبت نام نمایند

فرم  های درخواست در سایت زیر موجود است:

www.ephamradio.com

yagi antenna

باسلام

یکی از دوستان در شیراز انتن  یاگی تک و دو و سه المنت برای باند های مختلف می سازند جهت اطلاع و سفارش با ایمیلشان تماس حاصل فرمائید

EP7AHN@YAHOO.COM

نمونه کار ایشان که برای دو المنت 14  مگا ست ملاحظه میفرمائید

به امید موفقیت این دوست عزیز  اقای حامد نحرین  و حمایت از ایشان

با سلام

مطلبی راجع به فرستنده ساده 5واتی در رنج 7 مگابود جالب بود تقدیم می کنم

BUILD A 5 WATT 40 METER TRANSMITTER

As ham operators, we like to broaden our horizons by trying something new. There is nothing more

satisfying about this hobby than building your own transmitter. The circuit in figure 1 is a crystal

controlled CW transmitter with at least 5 watts of power. (The prototype generated 7 ½ watts) This

circuit was built on a Radio Shack universal board(276-168B) and worked extremely well the first time on

the air.

This circuit is unique in that it uses a power mosfet as a final rather than a conventional bipolar transistor.

The advantages are as follows:

a.)

Very high gain with almost 90% efficiency. (Only a small heat sink is required.)

b.)

Resistant to high SWR. 30 second key down with no antenna resulted in no dama

ge.

c.)

Power mosfets do not exhibit thermal runaway as with bipolar devices.

The disadvantages are that a bias voltage is required because the Gate threshold voltage can be

anywhere between 2 and 4 volts for any power mosfet. This bias must be adjusted for the particular

transistor installed in the circuit. In addition, a Zener diode is required to insure that the Gate voltage

never exceeds 20 volts. This circuit proves that the advantages far outweigh these requirements.

The adjustment of the bias voltage is critical and is adjusted by first turning R10 so that zero volts

appears on the Gate of Q4. Install an ammeter to the 13.8 volt supply voltage and apply power. At this

point the circuit should only be drawing just under 1 milli-amp. Now turn R10 slowly until the ammeter

reads about 5 milli-amps. This adjustment should never exceed 10 milli-amps. Turning R10 up too high

can cause damage to the power mosfet. Once adjusted, R10’s setting remains the same unless Q4 is

replaced.

All transistors can be purchased at Radio Shack and should not be substituted. Crystal Y1 is a 7.040

MHz crystal and can be purchased from Dan’s Small Parts & Kits or from Doug Hendricks. Send $3 to

Doug Hendricks, 862 Frank Ave., Dos Palos, CA 93620. (Specify 7.040MHz or 7.122MHz.) A small

heat sink is required for Q3 and Q4. S1 switches between transmit and receive modes so that no

damaging RF gets to the receiver being used. The frequency is fixed but a trimmer capacitor can be

installed in parallel or series with Y1 to allow some adjustment of frequency. Toroids can be purchased

from Dan’s Small Parts & Kits or from Palomar Engineers.

DE N1HFX

Parts List

R1

5.6K Resistor (Green, Blue, Red) ¼ watt

R2

15K Resistor (Brown, Green, Orange) ¼ watt

R3

2.2K Resistor (Red, Red, Red) ¼ watt

R4,R8

1K Resistor (Brown, Black, Red) ¼ watt

R5

4.7K Resistor (Yellow, Violet, Red) ¼ watt

R6

22 ohm Resistor (Red, Red, Black) ¼ watt

R7,R9

10K Resistor (Brown, Black, Orange) ¼ watt

R10

10K Trimmer pot, ¼ watt or larger

C1

.

01uf Ceramic disk capacitor

C2,C4,C6,C9

.1uf Ceramic disk capacitor

C3

.0028uf Ceramic disk capacitor (Use two .001uf capacitors and one 820pf

capacitor in parallel.)

C5

68pf Ceramic disk capacitor

C7,C10

.001uf Ceramic disk capacitor

C8

100uf electrolytic capacitor. (observe polarity)

C11,C13

390pf Silver Mica capacitor

C12

820pf Silver Mica capacitor

D1

15 volt Zener diode. 1N4744 or similar.

Y1

7.040 MHz or 7.122 Mhz crystal

T1

T50-2 toroid. 34 turns #26 wire for primary. 6 turns #22 wire for

secondary.

T2

FT37-43 toroid. 14 turns #26 wire for primary. 4 turns #22 wire for secondary.

L1

T68-2 toroid. 10 turns #22 wire.

L2,L3

T37-2 toroid. 16 turns #26 wire.

Q1

2N3906 transistor

Q2

2N3904 transistor

Q3

2N3053 transistor. Must use TO-39 or similar type heat sink.

Q4

IRF510 Power Mosfet transistor. Must use TO-220 heat sink(276-1363).

S1

Any suitable SPDT switch

تقويت امواج راديوئي با 32 ترانزيستور

سلام

جالبه 32 ترانزيستور براي تقويت امواج

مدار راديو با يك ترانزيستور

با سلام

اين راديو كلا از يك نوع ترانزيستور استفاده كرده

جالبه

چند مدار تست ساده

سلام

hommade yagi

yagi antenna

سلام

آنتن اچ اف تمام باند

سلام بر دوستان و سروران

با تبريك فرار رسيدن عيد سعيد فطر

اين آنتن توسط شركت alibaba بقيمت 62 دلار فروخته مي شود

Description:

widely used in military , water and so on emergency communications using antenna concealment , easy to set up , no debugging , do not need tune -day , you can work the whole paragraph 1.5-30mhz ,0 -500 km without blind , the effective distance and inverted v antenna rather, in the range of 1000 kilometers effective communication . " Even for those who do not can not be set back v friend, because it can be set up in various forms , can be horizontal , inverted v, triangle , the frame line , stayed out of the window and so on. Outdoor set up, more convenient , readily detected at the roadside to 0.5 meters above the length of the antenna above the tree branches propped up on it , the location could not straighten the antenna , there is no problem , let go antenna Raowan  type can be, one minute to get the antenna erection ! ! Is installed outdoors and special environment set up radio stations is a good helper ! ! !

Recently , concerns, and I like this antenna more people, but there is a need to make a grant to a friend now ! This antenna is very easy to set up , one person one minute can be set up is good, but the antenna is not required to debug , from 1.5 mhz - 30mhz standing waves are very ideal height from the ground is also not strictly required, more than 0.5 meters above the ground can be worked , outdoor gantry I also like to use it to do qso

1. Rated power : 100w, Operating frequency : 1.5-30mhz, transmit VSWR <2.0

2. the choice of brand GB black soft copper , hidden better

3 which batches of bigger and better selection of ring , so that argument is more ideal point oh ! Oh, can withstand high power 200W ( production , 200W high power for a long time to go through the test ) .

آنتن ماكسون

با سلام و آرزوي قبولي طاعات

ادامه مطلب آنتن در ادامه مطلب:

7Mhz short ended antenna

با سلام

آنتن 7 مگا كوتاه شده براي پورتابل و اپارتمان

 The shortened dipole for 7 mHz was described by Ken GM4JMU in Sprat 74. It is made from insulated wire - Ken used 24/0076. The coils are wound on 40mm ferrite as above, with 40 turns of the same wire on 1.5 ins PVC tube and may be water proofed if required. The balun at the centre is wound with miniature coax (RG174U). Tuning is best done in the clear and the preferred method of adjusting to resonance employed..

The same idea can be used to provide a mult-band doublet, by substituting tuned feeder for the coax.

The dipole described would be useful for the amateur with limited space and also for portable use.

آنتن 7 مگا و ارتفاع از سطح زمین

با سلام و ارزوی قبولی طاعات