"Porta-Combo" Version "P1" & "P2/P2a", PICaSTAR

IMPORTANT:- You MUST be a member of the Yahoo™ 'picaproject' Group for access to the latest files and software and to purchase these PCB's in the group buys. You need to join this group and digest all the information contained there on the project and especially the set-up information. Picastar was designed by Peter, G3XJP, who wrote a series of articles which appeared in RADCOM magazine and also RSGB handbook, 2006 edition.

You need, at the very least, to have read through these articles, for the backgound information, setup procedures and design details. In addition, information on coil and transformer winding is contained in those articles, that are now duplicated on the PICAPROJECT Yahoo Group pages. PICAPROJECT is not active as a reflector, it only contains files.

Carlos, EA1CGK's, magnificent build. JULY 2017

Jan 25th, 2015: Panadapter. page has been updated with more on the colour TFT version by Mats.

NEW March 20th, 2015: For those struggling to find the 2nd LO crystal, which is a custom made part, Terry, VK5TM, has developed a 20 x 30mm PCB to fit in the area of the crystal oscillator to provide either 10.710 or 10.715MHz output, selected by a simple link. It uses an Si5351 and PIC. Terry can supply the blank PCB and PIC already programmed. VK5TM STAR Local Oscillator Module for full info. Picture below.

Contact Terry directly please.... >> see QRZ.COM for email address.


  NEW Jan 25th 2015: 'P1' Build now on air ! Tony, G4CIZ Pascal VK2IHL has done a nice job on his build.
  NEW Sept 2015, Aurel has finished his 2nd STAR, this time with a Pandapter display also See builders pictures near end of this page.

NEW 1st Nov 2015 overlay link fixed.

NEW Jan 25th, 2015: For those struggling to find the 2nd LO crystal, which is a custom made part, Terry, VK5TM, has developed a 20 x 30mm PCB to fit in the area of the crystal oscillator to provide either 10.710 or 10.715MHz output, selected by a simple link. It uses an Si5351 and PIC. Terry can supply the blank PCB and PIC already programmed. VK5TM STAR Local Oscillator Module for full info. Contact Terry directly please.... >> see QRZ.COM (VK5TM) for email address.

March 20th 2015:- Here is Terry's 2nd LO PCB installed in VK3PE's Picastar, for testing. It would normally be fitted in the 2nd LO compartment to the left. In this case it was soldered to the walls of the Mixer area just for the purpose of testing as the crystal oscillator was already present.. Obviously, a top cover would also be fitted on the compartment also. Terry's module would be powered from the 10V supply rail in the crystal oscillator position, using the existing 100uH choke feed. No ill effects were observed using the Si5351 based crystal substitute, but vk3pe was unable to perform any actual measurements to see if there are any unintended problems.. Contact Terry, VK5TM, via QRZ.COM for more information on PCB availability.


Jan 25th, 2015: Panadapter. page has been updated with more on the colour TFT version by Mats.

Dec 27th 2014 R517 in MR area of schematic should be 2k2 in parallel with 1k2


Other PCB's.


Some experimental versions for extending response to 6m. Uses an MMIC as input device and different ferrite materials. Only a few available. I have NO original 20W pcb's.

These PCB's are a little shorter than the original G6ALU boards and use an ERA-5 (MMIC) in the first stage. The FET mounting holes are in the same position as the G6ALU pcb though. They are for experimenters to extend the range to 6m and maybe a little more. I have built one using 61 mix ferrites and the 'VHF' versions of the output FETS. Unfortunately, at present, I don't have all the details and test results due to some PC problems. One could build with the specified G6ALU parts and ERA-5 though, also.

March 20th, 2015:- Experimental schematic is here. No further information is available at this time.


Jan 8th, 2014 Wiring diagram for various displays added.

7th Dec, 2013: clarify RS232 adapter cable. See Schematics.

Please check here as you build, to see if any issues with the PCB's.

29th Nov, 2013: VK3ATC , VK3PE & F1CHM have been experimenting with a DSP based Panadapter

Update: 4th Jan, 2015, Mats SM0RJV has also done a lot of work using a colour screen.

YouTube screen shot.




** All pictures below show the "P1" version PCB. But, "P2 & P2a" are near identical.

Overlay updated FEb 2015


25th July 2013: the overlay drawing has been corrected (bottom side, top 3 bands had missing parts text)

24th Aug 2013:- New builder added ! Tony, G4LFU

16th Aug 2013: For sale !!! P2 PCB set including DSP and AF section loaded and tested, See this page for details. NOW SOLD

10th May, 2013 Toroidal BPF PCB's A few spares still available from a group buy.

6th May 2013, new P1 on the air, see builders section.

March 27th, May 6th, builders section updated. Four P1's are now on air !

** March 21st, Z2000 in the RTC charger clarified (see errors, BOM and Schematic areas this page)

March 11th, Integration drawing has been updated.

11th March, 2013 F1CHM, AC6AO and 4Z7LES builders pictures added.

*** 5th March, 2013: there is a missing ground on IC1604, pin 7 in the BPF area. "P1" only. (thanks Dan) ***

3rd March, 2013, pictures of cabling and VK3PE's build added in integration section.

Feb 22nd, 2013:- VK3PE's Combo P1 is now receiving signals ! See and hear it also here.

Feb 17th 2013: The OCXO and DDS in x4 mode is now working correctly ! (Thanks Ian for s/w fix) The Home made case is progressing well also.

As detailed in this web page, use of the suggested OCXO is EXPERIMENTAL. VK3PE now has new Trxavr software from Ian, G3VPX, running correctly in the DDS in x4 mode. The new version is Version 1.73 (Previous versions did NOT work correctly in multiply mode.) NOTE:- Phase noise will be degraded in 'x4' mode.

See above. (Click for larger picture) Not all parts are fitted. This is the result of about 12-14 hours of assembly so far. Having built a few Combo's, most parts are from extra's I bought previously. Tomorrow I will order the few parts I don't have. This build will be with the experimental OCXO in place of the Butler. It is not yet fitted in these pictures. The build will be tested with a TFTA PCB display already built up before. Plenty of coil winding to be done, a tedious part of the build.

I have powered up the DSP section and yes, the LED flashes !

Pictures may not be in focus !


This page may have links to other www.carnut pages. Please use the BACK key to return from those pages. (these are NOT fancy web pages !)

This is a variation on the previous single board versions called 'Combo" to build a PICaSTAR transceiver. PICASTAR was originally designed by G3XJP and the Combo versions use essentially the same module layout as the original, but combined to reduce wiring and ease assembly, by vk3pe.

NOTE: there is NO kit available for the PICASTAR project! The PCB's are usually made available as a limited group buy only. You need to have some experience in home brew of Amateur radio equipment although any keen Amateur is probably capable of building this multi-band HF (SSB/CW) rig. There are many facets to the build, you will need to purchase all parts yourself. A few parts are slightly difficult to obtain but not impossible by any means. You need to be able to fit or willing to learn, mounting some surface mount components. Some PC knowledge is handy also as you need to program the DSP code into the radio etc. Much friendly help is at hand though, if you join the Yahoo 'picastar-users' and 'homebrew-radio' groups. To obtain the software, you MUST also be a member of the Yahoo 'picaprojects' group.

There are also a number of ways to build and house the project, with some exciting display options available, from simple LCD through graphic types up to a full colour touch screen TFT display, either 4.3" or 5" in size. If you wish to fit a colour TFT display, then a TFT_A PCB is required, which is available only from VK3CG.

PICASTAR can be a very impressive radio to look at, depending on your skill level and facilities, or you can build it as simply as you wish. Performance is excellent for a home brew rig and there are many happy builders all around the world. If you wish, you can also build PICASTAR to the original design by G3XJP, including home etching of all the PCB's. All artwork, software and documentation is available on the Yahoo "picaproject" group. (This is not a discussion group, just a depository for G3XJP's many clever projects.)

Below is an example of a Combo PICASTAR, with 4.3" TFT display. It is not a P1 version build. The picture does not do the display justice, due to reflections. A version built with these newer 'Porta' boards is capable of being built smaller than this one although much will depend on what front panel options are used.

More pictures here

The "Porta" version is a repackaged Combo version that splits the previous single Combo PCB into two, to allow the building of a smaller footprint rig. The two boards are almost identical in size (about 9.1 x 7.1") and the idea is to mount them either side of a central chassis. The two boards are connected with a ribbon cable and some coax cables. The PA boards and Low Pass Filter boards are separate and as before.

Here is a pdf 'picture' from the PCB design to give an idea of the two boards. It can be printed out life-size. Side 1, side 2:- Either board can be mounted on top but it is suggested that the one with the BPF section be the top board. This 'picture' is taken from the PCB program and may vary a little, in the final board.

The paper printout shows the size compared to the older single board version. Of course, there are two of these boards now, suggested is to mount one on either side of a central chassis. NEW Jan 9th 2013

The boards are in two "panels". Once received by you, the boards can easily be separated out of the panels with a sharp pair of side cutters or a fine bladed saw. In some cases, you will also need to trim a little off some of the boards as you can see in the picture above. Use a fine bladed saw or cutters, then smooth with a small flat file.

SCHEMATIC: >>> covers P1, P2 & P2a versions with a page of explanations included.

UPDATED 27-12-2014: R517 is now 2k2 in parallel with 1k2., (was 2k2.)

RS232 cable details added. This cable unfortunately is different to that used by G3XJP on the homebrew PCB's. So, if you built H/B pcb's and made up a cable for the RS232, it is different on P versions. Sorry. Details are in the Schematic file (link above) and also here, in this drawing.

The schematic is essentially identical to the previous Combo versions of PICASTAR. It may include some options as the board can be built with some variations. See the next two paragraphs also please.

In the real time clock area, Z2000 zener diode may be reversed on the PCB, depending upon the brand and type you may buy. The correct Zener type is a BZX84-C5v1 or a BZX84-B5v1. If you have the 'reversed' type, you will need to rotate it on the pads until the correct connections are made. (If the diode is incorrect, there will only be about 700mV available at the output.)

The RS232 mode switch requires the fitting of a 1k resistor, across the active pins, to allow the S meter etc to operate. The simplest way to do this is to fit a leaded resistor under the PCB across the RS232 jack switched pins. See Schematic link above which has RS232 test cable details also. (Dec 2013)

17th May 2013: On the P2 and P2a version PCB, this 1k resistor is now mounted under the PCB, on the RS232 jack and is auto switched in and out.


Schematics, BOM etc for the PA's and LPF are not generally shown here. Refer to previous pages and G6ALU web site, for this information.

NEW Jan 2016: I have some information here which also shows plots of each filter.

Bill of Material (BOM) <<<--- Note: the BOM does NOT include the PA's, LPF, USB extender and Beeper PCB's. Or the TFTA.

8th Jan 2015: Current Bill of Material (BOM) for P1, P2 & P2a etc

Jan 25th, 2015: For those struggling to find the 2nd LO crystal, which is a custom made part, Terry, VK5TM may have the answer for you. Terry has developed a 20 x 30mm PCB to fit in the area of the crystal oscillator to provide either 10.710 or 10.715MHz output, selected by a simple link. Contact Terry via QRZ.com

This BOM text file shows the QTY of each item and is a text file only. > UPDATED 17th Dec, 2014 Use in conjunction with the Excel file above, please for details.


Feb 17th:- C320 is better NOT fitted, in the ERA-1 area. Slightly more output and flatter response. I will update the BOM soon.

Jan 6th, NOTE:- C20x value in the 2nd LO is shown as 47pF. VK3PE found that a lower value is required so that the crystal can be set to exact frequency. e.g. 18pF.

The BOM shows every part on the VK3PE STAR Schematics. BUT, not all parts are actually required, as it depends on various options and alternate part provision on the PCB's.

Note, there are a number of options and alternate parts fitting to allow for available footprint and parts etc. Generally, (except in the BPF section) a ref number ending in "A" is an Alternate part that can be used.

Parts for the PA's and LPF are not in the above BOM. You need to refer to the G6ALU web pages for those BOM's.

READ THIS, it also helps on parts supply sources.

Notes for building this version (.doc file) Information on parts, how to build etc. pdf version

Component overlay by Value of parts. Use this for quicker assembly of the PCB's.

18th Feb 2015 P1, P2, P2a overlay R525 & R526 are Not Fitted. (NF)

PLEASE NOTE > LED's in the matrix area are shown incorrectly on the "P1" PCB only. For the P2 & P2a version PCB, this has been corrected and the P2/a PCB overlay link above is OK.

PA's, LPF etc Please use in conjunction with the G6ALU web page information. G6ALU's web pages

Problems with the "P1" & "P2/a" PCB's?

If problems are found, updates will be posted in this section.

NOTE:- all of the PCB's are electrically tested [E-Test] by the PCB vendor (at extra cost) but is NOT a guarantee that there may not be a sliver of unetched copper shorting a track or pad, on an occasional PCB.

P1 version:-

Jan 31st; there is a small sliver of copper shorting some tracks. It's on the "D-ground" copper, under the PCB in the CODEC area. You will see a small copper join to the groundplane. This should be cut with a sharp knife. Feb 13th"- Here is a picture of where to cut, under the PCB in the CODEC area.

3rd Feb, the holes for most of the headers seem to have been drilled slightly undersized. Parts can be fitted but press them in carefully and slowly. Some builders have scraped off the corners of the header pins, with a sharp knife, or sanded down the pins on the connector to ease fitting.

5th Feb, the holes for the LM317 regulator, if you use the OCXO option, (but see note at start of web page) are too small. You may need to trim the pins of the LM317 down to suit.

There is unwanted solder mask under the 1.8 and 3.3v regulators (IIC2/3/4) in the DDS area. Best to scrape the resist off under the three regulators with a sharp knife, so the tab can be soldered to the PCB copper.

11th Feb, PLEASE NOTE > LED's in the matrix area are shown incorrectly oriented on the PCB. The overlay "A" & "K" and arrow, (link above) has been corrected in the drawings only. The overlay on your PCB is incorrect.

5th March, 2013: the ground of IC1604, pin 7,8, is MISSING. Please add a small wire link from pin 7 to adjacent ground on the Capacitor, C1506 ( a short piece of wire from an electro capacitor or leaded resistor is a suitable wire to use.)

March 19th, 2013: In the real time clock area, Z2000 zener diode may be reversed on the PCB, depending upon the brand and type you may buy. The correct Zener type is a BZX84-C5v1 or a BZX84-B5v1. If you have the 'reversed' type, you will need to rotate it on the pads until the correct corrections are made. This updated Sch page shows the area and also some suggested Element14 (Farnell) catalog numbers. (this page has NOT yet been added to the Schematic download on this page.)

Aug 14th, 2013: Pin 16 of connector "JT6" in the Trxavr area, is not connected to ground. This only affects those using an LCD display and can be overcome by using the ground conenction on pin 1 instead.

Problems with P2 Version (the above errors are fixed on the P2 version but still check the Z2000 diodes.)

Aug 14th, 2013: Pin 16 of connector "JT6" in the Trxavr area, is not connected to ground. This only affects those using an LCD display and can be overcome by using the ground connection on pin 1 instead.

Problems with P2a Version

[Oct. 2013] "P2a" is a slightly modified version of the P2 pcb's.The JT6 ground problem in P2 is corrected. BOM and schematics remain the same.

The schematics now have a page for making the Cable but it is also detailed in this drawing (click here).

So, for "P2a" there are NO known errors.

Jan 2015: One builder has reported manufacturing fault in the PCB around the audio amp stage. Some small slivers of copper have shorted the 12v tracks to adjacent ground areas. Inspect carefully if you have problem with power supply short.


Dec 2013, For those who built G3XJP's PCB's, I am afraid the RS232 cable for all of the "P" version PCB's is different. The pinout is REVERSED. (Murphies law?)

Not an error, but the DDS amplifier, and "ERA-1" (from Mini-Circuits) works better if C320 is removed. Output is about +8dBM.

VK3PE's P1 build progress. Trxavr is controlling the DDS, driven from an experimental OCXO reference. The regulator gets quite warm, it may need additional heatsinking or perhaps a dropper resistor on the input supply to the LM317. (LATER:- an additional smaller heatsink was bolted on the rear of the larger one)

The other PCB section is almost complete. The DSP LED flashes too! I normally load and wind the BPF coils etc last in my builds. Unlike previous COMBO boards, the RS232 port is now a stereo jack, to save space.

22nd Feb 2013, the Combo P1 is now receiving signals. After some issues with a dodgy ATMEGA chip (bought out of China on ebay) very pleased to report the VK3PE build has received it's first signals on 40M today. Sensitivity is on a par with previous builds. (~-127dBm) The BPF is not yet fitted. Some more work to do on the case to tidy things up from the "bench" tests to go. Excuse the messy work bench too ! Click here to see and hear a QSO on 40M. (4MB AVI file)

click picture for larger size.

NEW:- Feb 13th, 2014 You might notice I hand wound the two inductors (L3301, L3302) in the DDS filter area. The values are from 'Bob's mods' and are not off the shelf part values. Some builders use toroids, I elected to use air wound. They were calculated from an on-line calculator and confirmed with an AADE LC meter. For a closeup look at them, a picture is here. It includes the winding information.

NEW, 3rd March, 2013: There are more pictures here of the build so far which will also give you an idea of the interconnections also.

See link above for more details of the VK3PE build and homebrew case.



Occasionally, a group buy for Homebrew-radio Yahoo group members is undertaken.

November, 2017, there are NO current plans to order PCB's.

Cost has risen I am afraid, mainly due to the plunge in AUS Vs US$ exchange rates. When I started making 'P1' version, the rate was $1.05. It's now around 68c and still falling. (bank rate) This impacts severely on the final cost. This means the PCB set cost is close to AUS$100. Sorry, nothing I can do about this.

This includes postage, packing materials and Paypal levy. NB. TFTA pcb is not included. (refer to VK3CG)

Please note... there is no insurance or tracking offered on the postal service. Future orders (if any) may vary in cost (up or down) as there are many factors involved in the group buy.

Enquire. EMAIL VK3PE, see QRZ.COM


The "P1"and "P2/a" version PCB set includes all of the PCB's you need only, (it is not a kit, no parts are supplied) , to build a working PICASTAR:-

The main "P2a" PICASTAR boards, combined into two parts as above, plus;

20W PA, 140W PA and LPF boards. (The P2/a panel now also includes the end pcb's for the 140W PA output transformer.)

A remote USB interface PCB. This PCB allows the USB port to be extended to the rear or front panels, as you wish.

A small PCB to make the original G3XJP optical tuning encoder. Some builders use commercial encoders though. NB: the original type specified is 180 pulses.

A low probe voltage "Beeper" board for testing. Beeper board schematic. The BOM kindly supplied by Bill, N4BKT, 31st Dec 2009. Beeper board wiring diagram

Use this Beeper board to check connections etc with low voltage probes, which won't damage any parts. It is suggested you make this PCB FIRST as it will give you a little practice with SMD parts and wiring etc.


What is not included is the colour display interface board, called "TFT_A". This TFT_A board is only available from VK3CG.

UPDATE, 29th Nov, 2013, It's believed that VK3CG may have now run out of full kits, but plenty of the TFTA PCB's are available. Check directly with VK3CG. There is a Yahoo TFT group also, where you can contact VK3CG.

The correct type of 4.3 or 5" TFT display needs to be bought off eBay. Details are on the TFT users group.

Please note, this project can be fitted with up to 8 optional Encoders which can be programmed for various tasks. Provision for this is part of the TFT_A board. If you do not fit the TFT display, then the encoders will require an additional interface board (Encoders8) which is NOT included.

Trxavr 'Controller' & CHOICE of DISPLAY

PICASTAR originally used 6 x 7 segment LED displays. Later, Ian, G3VPX, developed a new controller, called TrxAVR. ( This controller is integrated onto Combo P1 & P2/a and allows the use of more modern displays using LCD's and later, also catered for a full colour TFT display.)

The Trxavr section of the Combo P1/P2 board is included in the BOM for the main PCB. You need to refer to G3VPX's web pages for full info on programming (including the software) of the Trxavrb section. Also, the TFT display.

See here:- G3VPX's TrxAVR Interface web pages.

NOTE:- There is currently no PCB for an 'Encoders 8' PCB. Schematic This would be required if you wish to fit encoders without a TFT display. The set of PCB's supplied assumes most will use a TFT display.

To use the TFT display, a separate PCB, (not provided with COMBO) is required. TFTA PCB's are available from VK3CG. VK3PE does not have permission to sell this PCB. It is NOT included in the boards supplied by VK3PE.

Suggested display wiring diagrams.

Please ensure you have data for the display you wish to use, as pin-outs can vary. This diagram shows the wiring from the Combo PCB, in the Trxavr controller area.


The TFT display interface PCB was designed by Chris Stake with software by VK3CG. It can only be used with the Trxavr controller which is on Combo boards but is not a part of the priginal G3XJP design. It can be retro fitted though.

The actual TFT display can be bought in either 4.3" or 5" sizes on eBay and other on-line stores, very cheaply. (typ. $25) Touch screen types are also catered for in the design. An estimate for the TFT display option is about AUS$90 - 100 which would include the PCB and parts plus the TFT display itself. See the information in the files section of the Yahoo "TFTA_Central" group for correct TFT models.

There is some information here on setting up, and programming the TFT PCB if you are fitting a TFT display.

Remember, a "TFT_A" interface PCB is required to use a TFT display.

NOTE: some TFT displays are better mounted with the ribbon cable at the bottom, as the viewing angle is better. Check yours before final fitting into case. The TFT_A PCB has provision (with a link) to 'invert' the display in software.

Other LCD displays can also be used, both character based and graphical. (Not touch screen though) Refer to the "Combo C" version pages for information on connecting these types.

Band Pass Filter section.

The BPF is closely based on the original design by G3XJP, but the inductors are now on the top and Lodestone formers can now be fitted. The recommended Toko™ and some other '10mm' types can be fitted also.

http://www.Digikey.com in the USA have the FST3125 and FST3126 devices, for example, at reasonable costs but shipping should be factored in also. A group buy would be better, as costs drop rapidly with increased numbers bought.

There is some information here and here (coil winding) which may be useful for coil winding, if using Toko 10K™ formers.

Toko pre-wound coils are more difficult to buy these days, but some data here may be helpful. Some builders have fitted small Toroids with good results, but it's quite tedious to tune them. No information is currently available on toroid type and winding details.

PA3AKE has done a lot of work in developing a very high performance BPF. Some builders have fitted this in place of the PICASTAR BPF but be aware that the PA3AKE BPF is very large. There are some pictures here of one PA3AKE build. Some have built a smaller version of the PA3AKE BPF with homebrew PCB's by using smaller toroids. Performance will be lower than the original PA3AKE version, but probably more than adequate. The Trxavrb controller and Hobcat allows this BPF to be fitted using an I2C interface which is included on version P1 boards. (PCA9555)

Dan, AC6AO, has built a toroidal version BPF using the existing STAR PCB's.

Expanding on this idea of using Toroids in the BPF, VK3PE has made available some small PCB's that can be fitted with a Toroid version of the BPF filters and be fitted over the appropriate band position on the Combo boards BPF section. NOTE: this is essentially experimental as VK3PE has not fitted a full set of these PCB's to his own STAR builds, but it is very similar to the toroid version by Dan, in the link above. In fact, the winding information is based on Dan's good work.

10 of these were included on a "Toroid BPF" panel which may still available from VK3PE.

More Toroid information on this new page. Toroid adapter PCB's for BPF


The PA3AKE front end, as built by G3VPX.

If you decide to use the PA3AKE front end BPF, Trxavrb controller has provision for setting bands with the PA3AKE BPF in the Hobcat setup program. The BPF on the Combo boards is easily bypassed and of course, you will not load those components.

TOKO™ Coils

G3XJP's original design used Toko coils. While no longer made, they can still be found on eBay, in old CB radios and new from some suppliers in the UK, although not all of the part numbers specified by G3XJP are available. Mostly, you will need to rewind any Toko coils found. Refer to the information and links above. The P1 and P2 pcb's can take Toko coils and also Lodestone types. 'Slot-10' can also be fitted but their Q is not so good.

There were some Toko style coils on ebay at one time with only a single winding area. I don't know if they are usable on all bands, if at all, but one builder has played with some and I include his 20M band info here. And also 160M here. Leonid has given me some preliminary winding details for each band but please note, these are UNTESTED and are not guaranteed to give exact equivalent BPF's to that using the specified Toko 10k coils. For example, the IP3 or bandwidth might well be poorer.

LODESTONE™ and also Slot-10 Coils

The PCB will take these Lodestone coils also and in fact, they are reputed to be a better part. They cost about $2.50 each and occasionally a group buy will take place on the Yahoo groups for those interested and the price will fall a little. VK3PE has no direct knowledge of where they they can be purchased though but would assume somewhere in USA.

Suggested Combo PCB build method.

Wondering where/how to start? Check here. This is for the "B" version, but "P1" & "P2/a" versions will be very similar.

The above link pages are not an official PICASTAR build method. You should also have read all of the original articles by G3XJP, located on the Yahoo "picaproject" group. You need to be a member of this group to obtain the documents and software.


UPDATED! March 11th, 2013. The integration drawing (3.2MB) now updated, mostly just tidied up.

Feb 8th, 2013, (this is the older drawing, for reference only) An integration drawing (draft) (2MB pdf) is now available, to assist with the inter-wiring.

If you see anything that is not clear, let me know.

23rd Feb, 2013: There are more pictures here of the build so far which will give you an idea of the interconnections also.

CABLES: There are pictures here which will give you an idea of the interconnections

The two main PCB's connect together using a 20 way IDC cable. Plus, a 10 way IDC cable connects to the LPF board. NOTE: only one end of this 10 way cable uses an IDC connector as the LPF has a single row of pins..

A 4 way cable connects the DSP 15KHz signals and the cable is passed through a small cutout in each PCB which has been arranged to be over the top of the lower PCB to allow the cable to be passed though a hole in the chassis, if desired. It is optional to use the cut-outs.

Several small co-ax cables (eg RG-174 etc) are fitted under the PCB's for RF interconnects. Also, small co-ax (eg RG178) is used to connect the main PCB (BPF area) to the LPF and 20W PA input. Provision for fitting SMA connectors is on the PCB but this is not mandatory. You can simply solder the cables to the PCB's. RG178 is often found on eBay.

A twin core shielded audio cable is also required between the Trxavr section and the DSP RS232 switch area.

DC power input [13.8V] is connected to the PCB using 'quick connect' tabs or QC tabs. The DC supply passes through a reverse polarity protection relay to more QC tabs, for connection to the PA's. Don't skimp on the cables used as high currents are involved here, especially if running the 140W PA. Use two parallel cables for the 140W PA. Also, make sure the PA's are well grounded. I usually use some co-ax cable braid from the PA back the DC input area.

RS232 Cable. You will need to make a test cable for using G3XJP's various programs and laoding DSP etc. The cable detail is DIFFERENT to that used by G3XJP and is detailed in the schematics. Refer to link above for Schematics download.

Making the shields, a suggested method. Shown for earlier Combo versions, but principle is same for P1, P2 etc version.

All versions of the Combo board require shielding around the various circuit 'blocks'. However, you can build the whole radio without them initially and test it first.

And updated with info from Dan Rae

High SWR protection. There is an input on the TIMER section (PIC16F627) for disabling the transmitter ("TX_DISABLE"), if high VSWR is present. This requires an additional board that integrates into the Trxavrb controller firmware and is NOT supplied with the VK3PE board set. With this PCB, forward and reverse power is indicated on the TFT screen when in Tx mode.

Further information on this option is here on G3VPX's web pages. NOTE, the TIMER PIC code needs to be the one that has been modified by G3VPX for this purpose. (It disables the PA if there is high SWR) This might be found on G3VPX's web pages, I think. Or possibly is part of the Hobcat download files and already on your PC. You will need to download Hobcat anyway.

A 'commercial' PCB is not normally available for the "peakswr" protection. A copy of the pcb copper for home brew is on Ian's web pages.

April 2014: VK3PE had a small number of these made, with some small changes to Ian's original. eg. The relays are no longer used for peak switching. FET's are used instead. In my initial build, I used an LM324 op-amp. This is not the reccomended part! The original design uses a rail to rail type op-amp. Using an LM324, the output positive excursion will be limited.

NB This PCB is a little shorter and slightly wider (100mm x 43mm) than the original (right hand picture). Overlay. BOM. BOM (Xcel) Schematic.

Only a few ( 8, . one left) of these PCB's available:- AUS$8.90 incl. postage anywhere. NONE left.

Need Ideas to build your PICaSTAR ??

There are more ideas on building in the Builders pages.

Also, see the link on Combo "B" version builders pages.

Latest entries:

Cristi, YO3FLR.

Enno, DK5NOA.

Sanyi HA2NJ has updated his modular STAR with Trxavrb and TFT

Nick, UY5QQ's modular STAR build is now receiving signals. 5th May 2014

Carlos, EA1CGK's magnificent build NEW July 2017


Some ideas on tools etc. This is for the modular STAR but might be of some use.

Need a CASE and would like to make one? Some ideas here using aluminium extrusions.

Here are two fine examples using PCB material for the case. [Left Star uses a 128x64 display, right uses a colour TFT display] Roger had a supplier pre-cut the 2mm thick PCB material for him, to save some work.

Here (below, left) is a typical 'old' instrument available on eBay that can be stripped and used to make a nice case for your STAR. This one is probably not available still but was titled "General Signal Tau-Tron S5104 DS1-DS1C-DS2 Digital Transmission Test Set PARTS " and was only $28 plus postage. Within USA postage was reasonable but watch out if you are not in the USA as this vendor charges over the top for shipping ! However, it will give you a good idea on what to look for and you can see just how nice these cases can be, as the picture by Dan (AC6AO) shows, using this same case. Always ask the vendor for the dimensions BEFORE buying though.

Dan, AC6AO's build (click for bigger picture)


Mats SM0RJV Jan 4th 2015:- (below) Home built PCB's now on air. Magnificent work. Mats has also built a TFT based Panadapter.

BUILDERS PAGES, Combo P1, P2, P2a versions.

A few of the builders have now made excellent progress on their new Combo "P1, P2/a" builds. Here are some, that sent in photo's. Click on the pictures for even more information.

Michel, F1CHM

Now on air !! 27th Mar, 2013


Dan, AC6AO

Dan is well advanced


Leonid, 4Z7LES


Glenn, VK3PE (author of this page)

Aurel, YO5OCA


Aurels 2nd build with 64KHz wide Panadapter also (Elm-ChaN design) Sept 2015


Roger HB9LFU

Roger, HB9LFU


Tony, G4LFU

Picture clearly shows the intended 'stacking' of the P series PCB's.

More from Tony, his P1 build now in a case.

Click to see more details

Ken, G3LVP, P2 now on air.


Dave, M5TXJ has almost finished assembling his P2a PCB (click for pictures)


John, G0IJK's "P2a" build progress. Oct 2014. Click picture for more. NEW Updated Jan 2016

April 2015 Michel, F1CHM, sent me these pictures of an incredible 9th Picastar build.

NEW June 2016:-........ Earle, AB6WL, has made his own versions of Star boards. eg upper left DSP & Codec, upper centre, AF amp RS232 & opto. Bottom, Trxavr-Matrix-Timer.

NEW June 2016:-. Yuriy, UW5EHL, almost has his Combo Star finished. (picture below)


Carlos, EA1CGK's magnificent build NEW July 2017


Dan, AC6AO
Michel, F1CHM --> updated 050415
Leonid, 4Z7LES
Glenn, VK3PE
Aurel, YO5OCA 6th May 2013 2nd Build Sept 2015
Roger HB9LFU P2 almost done
Tony, G4LFU Jan 2015
Ken, G3LVP Nov 27, 2013
Dave, M5TXJ
John, G0IJK, Updated Jan 2016
Bill, N7OQ Nov 6th 2014 Classic H/B Star
Tony, G4CIZ Jan 2015
Pascal, VK2IHL Jan 2015
Johnathan Kelly NEW 7th March 2015 Classic Star
Carlos, EA1CGK July 2017


Some IDEAS ON HOUSING YOUR STAR -->> NEW 26th Jan 2013

This a drawing of how a front panel could look, trying to keep the size to a minimum, consistent with the smaller PCB size of the P1 Combo boards. You can make a layout as you wish of course, larger and maybe even smaller if you are able to. One way would be to use an LCD display and no encoders except for MENU. The Mic. Socket could also be relocated to the side of the case. (The width of the PCB also needs to be accommodated. In this drawing, the case is wider than the actual PCB behind) A layout like this would probably also need a custom made case in aluminium or made with PCB material unless you were very lucky finding a suitable case to use. The size of this panel is 220 x 110mm in size. Those dealing in inches might have to convert this! [divide by 25.4] Click the picture for a pdf version, also. It should be printed with no scaling, for an A4 paper sheet.

Feb 17th 2013: VK3PE is currently building a home brew case based on drawings below. Although now 240mm wide, to accommodate the 4x4 keypad instead. Only one encoder (Menu) is planned for the build, although may add more later.

Below is the progress so far. Based on the ideas below but 240mm wide as described above. Some changes to the drawings (originals still shown here) were made to suit the construction better. Case is made from 100mm "U" shaped aluminium extrusion. This type has a 25mm flange and is 3mm thick. For those dealing in inches, about 4" x 1" x 1/8" thick. In my build, I elected to cut the top flange down in width, for better internal access.

A sub chassis plate is mounted on some further angle extrusion mounted down low. The PCB with the BPF section it, is visible. The other board will be underneath. An upper sub chassis will be added later for the 20W PA & LPF. The 140W PA, if used, will go on the back with suitable heatsink.

Click for larger picture.

March 2013, Above is a home brew matching power supply and speaker enclosure, made using 60mm high "U" shaped extrusion to the same dimensions as the Transceiver, in a similar fashion. Not quite finished as yet.

This is similar to one built by VK3PE, above.


The above drawing is for information only and provided as a guide. Any layout is possible, you may prefer the tuning encoder on the other side for example.

** No panels or parts are supplied by VK3PE. **

A minimal PICASTAR using Trxavrb controller, only requires a display (TFT or LCD), the keypad, tuning encoder and MENU encoder.


The pictures above are not necessarily a "how to build this radio", just to get you thinking on making your own PICASTAR. They do not include internal speakers or power supplies. Everybody will have their own ideas on construction. I would be happy to include any builders ideas and pictures of their build, on these pages.


Making a tuning encoder. A PCB is supplied for this as per the original G3XJP design, and the parts to build it are included in the BOM.

Some builders use encoders off eBay. The recommended pulses per turn is 180 but these are not easily available, so many use 120 or even 256 pulse commercial opto encoders, which will obviously affect the tuning rate, when used in STAR. A common encoder found on eBay is the Oak-Grigsby 120 pulse type at reasonable cost (about $30 or so). They tend to be a little stiff to turn but work OK. ie they do not 'spin'. Avago make very nice encoders but these tend to be in the order of $100 and more.


Yahoo groups which are very helpful in this project.

You MUST be a member of the Yahoo™ 'picaproject' Group for access to the latest files and software. You need to join this group and digest all the information contained there on the project and especially the set-up information.

It is also very helpful to be a member of the 'homebrew-radios' and 'picastar users' groups. Refer to those groups for information on joining. For the later, you must be a member of the above picaproject group also.

If you wish to fit the colour display option, there is a 'TFTA_central' Yahoo group also.


For future group buys of PCB's refer to email below please.

NOTE ! These PCB's were prepared in good faith, as a labour of love. Although carefully checked and preceded by the previous Combo versions, errors can occur in design and also in the PCB making process. <vk3pe>



This page will be updated further when more information is available.





Page created on 18th Dec, 2012 by vk3pe & last updated on November 20, 2017