This is my first attempt at homebrewing a transceiver circuit and the first experience with the construction of an SSB rig. I had previously constructed many small CW and AM rigs including the VWN QRP and many other experimental circuits.
I recently got my license renewed and I was very happy with this. I have not been on the air for some time and so I decided to homebrew my all indigenous tranceiver. There were many circuit ideas and TRX circuits in front of me and I chose VU2HMY circuit as I was told it was quite easy to complete and operate. I am taking this time to go through a step by step construction presentation of the VU2HMY circuit. I am also getting further construction guidance from Anil Kumar VU2JQX who is a friend of mine in Trivandrum.
I had ordered for a circuit board by contacting Dr. Rajasekar VU2HMY via phone and got excellent communication from OM Dr. Rajasekar. Within 2 weeks of ordering the board, I got my circuit board through the courier post. To my amazement I got some of the Xtals included with the circuit board and I was relieved from the job to peak up the SSB band pass as all the Xtals were matched and now I only have to wire the other stages. I immediately procured all the components that are necessary for the construction of the rig for a good start.
VU2HMY TRX Project:-
I decided to start with the power supply and the audio sections first for the construction of the TRX project before going through the other sections. I already had the switched power supply with 9 volt and 12 volt range.
VU2HMY circuit board and the necessary components for building the TRX
The wiring platform that I have is a small one and so most of the tools I have to place it closeby.
A closeup view of the board and the components.
Audio Stage:-
The audio is wired around the LM380 audio IC. It is a 14 pin IC and is expected to give around 4-5 watts of power to the speaker output. As you can see all the components that I have wired around it. First I soldered the IC base in position on the board and then after soldering all the related components, I inserted the IC into its base. I tested the audio and it did give a good sound output to the speaker. Then I soldered the BC548 into place, which was supposed to be the audio predriver stage and then the audio filter stages respectively and tested it again and everything worked fine. The audio output terminals were to be terminated with the connectors that I found it difficult in procuring, but then I could get it from an electronic shop. You can also see the other IC bases that are soldered to the board.
As I was a little QRL the project is a bit slow but my enthusiasm for the project keeps me going on for completion of the project and I hope to finish the other stages in time. The next stage that I am planning to go through is the product detector/balanced modulator.
The audio side of the TRX consists of the LM380 IC, the audio predriver and the filter stages.
Product detector Stage:-
I just soldered my product detector stage, built around the TA7358 IC. The circuit also has the carrier oscillator stages designed within the IC, only those passive components that are needed to be connected externally through the PCB. The frequency for USB and LSB operation are produced by 2 x-tals both above and below the 10 Mhz frequecy through switching. At the first instance my product detector was not working perfectly even after many trials, so I am suspecting a need for an IC replacement. Hope to rectify it later though!
The product detector stage using the IC TA7358.
In the meanwhile I wired the other stages that are necessary for the DSB signal generation which includes the mic amplifier stage and the band pass filter stages. Also completed the CW side tone oscillator on the audio side. Hope to start the mixer stage after this.
Here after a while with some QRLs and other issues. Did some stages during the time being including a product detector, an external audio amplifier to improve the audio level, and a VFO.
External audio amp
Power supply
Product detector
The VFO
I recently got my license renewed and I was very happy with this. I have not been on the air for some time and so I decided to homebrew my all indigenous tranceiver. There were many circuit ideas and TRX circuits in front of me and I chose VU2HMY circuit as I was told it was quite easy to complete and operate. I am taking this time to go through a step by step construction presentation of the VU2HMY circuit. I am also getting further construction guidance from Anil Kumar VU2JQX who is a friend of mine in Trivandrum.
I had ordered for a circuit board by contacting Dr. Rajasekar VU2HMY via phone and got excellent communication from OM Dr. Rajasekar. Within 2 weeks of ordering the board, I got my circuit board through the courier post. To my amazement I got some of the Xtals included with the circuit board and I was relieved from the job to peak up the SSB band pass as all the Xtals were matched and now I only have to wire the other stages. I immediately procured all the components that are necessary for the construction of the rig for a good start.
VU2HMY TRX Project:-
I decided to start with the power supply and the audio sections first for the construction of the TRX project before going through the other sections. I already had the switched power supply with 9 volt and 12 volt range.
VU2HMY circuit board and the necessary components for building the TRX
The wiring platform that I have is a small one and so most of the tools I have to place it closeby.
A closeup view of the board and the components.
Audio Stage:-
The audio is wired around the LM380 audio IC. It is a 14 pin IC and is expected to give around 4-5 watts of power to the speaker output. As you can see all the components that I have wired around it. First I soldered the IC base in position on the board and then after soldering all the related components, I inserted the IC into its base. I tested the audio and it did give a good sound output to the speaker. Then I soldered the BC548 into place, which was supposed to be the audio predriver stage and then the audio filter stages respectively and tested it again and everything worked fine. The audio output terminals were to be terminated with the connectors that I found it difficult in procuring, but then I could get it from an electronic shop. You can also see the other IC bases that are soldered to the board.
As I was a little QRL the project is a bit slow but my enthusiasm for the project keeps me going on for completion of the project and I hope to finish the other stages in time. The next stage that I am planning to go through is the product detector/balanced modulator.
The audio side of the TRX consists of the LM380 IC, the audio predriver and the filter stages.
Product detector Stage:-
I just soldered my product detector stage, built around the TA7358 IC. The circuit also has the carrier oscillator stages designed within the IC, only those passive components that are needed to be connected externally through the PCB. The frequency for USB and LSB operation are produced by 2 x-tals both above and below the 10 Mhz frequecy through switching. At the first instance my product detector was not working perfectly even after many trials, so I am suspecting a need for an IC replacement. Hope to rectify it later though!
The product detector stage using the IC TA7358.
In the meanwhile I wired the other stages that are necessary for the DSB signal generation which includes the mic amplifier stage and the band pass filter stages. Also completed the CW side tone oscillator on the audio side. Hope to start the mixer stage after this.
Here after a while with some QRLs and other issues. Did some stages during the time being including a product detector, an external audio amplifier to improve the audio level, and a VFO.
External audio amp
Power supply
Product detector
The VFO
Hi,
ReplyDeletecan u post the circuit and other details?..it would be more useful...
VU3PKQ
Sinosh
Hey Sinosh,
ReplyDeleteYou can get the circuit diagram online by a google search and you can also get the PCB directly from VU2HMY by visiting his blog. http://vu2hmy.blogspot.com/
VU2LVJ
Lesley
Hello Sisk,
ReplyDeleteGreetings from India! Though I am not able to read your comment, hope you enjoy this project.
VU2LVJ
Lesley
Just an FYI. Those comments are SPAM. He is just putting his site links on your blog to gain some popularity (from backlinks). Its best to delete such comments.
DeleteIs there anybody who can help to assemble the rig and give it to me if I pay for his time and expenses?
ReplyDeletevu2bjp@yahoo.com
Nice blog Lesly.
ReplyDeleteI just picked up HMY boards on Hamfest india 2009, VU2HMY gave a fantastic talk in the technical session here in Bangalore, I would be starting my Homebrewing of HMY Transreceiver shortly.
DE VU3NEO
Handle: NEO
QTH: Bangalore
The torroid coils of VFO board not mentioned in the schematic diagram..assmbing almost over still i need some styroplex capasitors...VU2CRD...09042856696
ReplyDeleteKeep up the good work friend....VU2SGW
ReplyDeleteDear Dr. Raj sekhar sir,
ReplyDeletegreetings of the day, Kindly consider me to let me know when you are going to start Ham RAdio Classes for learning Ham radio trouble suiting correction. please. Syed MOhiddin Basha, VU2VIZ. Cell No. 09985037725
I am also working on the same project, similar and I have successfully got the PD section working. Infact I have also assembled the same section and tested it. I have a small video which I would be posting on the net soon, so maybe , you can comment on it. I am now working on selecting the Xtals for the ladder filter, that's 1 hell of a job. I am working on a similar design using the same circuit.
ReplyDeleteregards
VU2UPX
http://youtu.be/PE6B4W9Ahkc check this out.
ReplyDeleteGood Morning Dear sir, have Nice Greetings relating to Friday... 73 De VU2VIZ Syed Mohiddin basha,
ReplyDeletehas anyone completed HMY board and operating it. vu2mua.
ReplyDeleteHas anyone brewed the HMY2k8 transceiver and what was the exprience, problems, difficulty and its solutions, is there any peer group to help.. anyone , de vu3inj.
ReplyDeleteVague board, No workable hex no support
ReplyDelete