Monday 29 September 2008
I was sorting out a small box in the study and found a couple of new 1 pole 12 way switches and thought what could I use these for....
Simple ATU for qrp field radio. I found this (thanks JN1GLB) and thought it would be ideal.
I do not have 100R 2W resistors but I do have a supply of 47R 5W or 10W resistors so will use them instead. Also I have some nice Ge diodes so will use one of them. Lots of red LED available. Not yet had beakfast so thought would wind the toroid using some coloured craft wire XYL bought me the other day and connect it up to the switch. It is easy to wind and make the taps so that the toroid when set in the middle of the 12 way rotary switch means the switch connectors are by each tap point. Salvaged a big poly varicon meter said >400pF so will use that, and have a set of 4mm binding posts, with banana plug sockets so will use those for the antenna connection.
Put it all on the bench and works fine...now I know I have a deep ABS box somewhere .... can wait until later!
Got to find a project for the other one now.
Sunday 28 September 2008
This is not a commercial attempt as a reintroduction of this I was interested to look at kits GQRP has covered in previous issues of SPRAT and as I am building some single band cw rigs this seemed like an excellent candidate.
An inside shot from one of the respondants from the GQRP list to my plea for help sent me this. It has helped a lot with the PCB layout.
The construction is a bit odd with the top ground plane being used for the ground side of the through hole components, so many have only a single hole. It is more usual o have a ground plane on the bottom of the PCB and to use a solid ground plane on the top surface. If possible using through hole plating. I will look at this.
The original documentation available on the web contains little about the track layout but there is a construction diagram which aided with the layout.
When I get the PCB finished, etched and tinned will update the post.
All the components for this were available from the usual sources, cannot say junk box as almost everything in the shack is new or new old stock. Chris and Peter at Jabdog (original kitted this BTW) came through in excellent style with all the missing components.
Friday 26 September 2008
Few days after the fact but on 21st September I gave a talk about my DX activities to 3B8 back in march.
The venue was hogcon which was notified to many here.
The hogcon website is here but the web blog of the group is also worth a read here
Anyway I am heghog #8 and I talked to a small group of qrp enthusists and it was great fun.
My transport to it (as 34 miles from home) was by bicycle and traina nd I cyccled from Cambridge to Royston on the A505 and then caught the train from Royston to Stevenage.
I as a few others did took latest homebrew projects to an informal show and tell.
Lunch was a coke and a burger from and BBQ. After the talk operated GB2QRP running SSB with me at the mike and worked a couple of stations.
Anyway having almost forgot it I noted a post here
that they had published the design so I jumped in and started to figure out what was involved. One thing led onto another and i setup a yahoo group to support other builders and I arranged for the first group buy of components. In the end I asked Peter at Jabdog to supply all the components and to purchase some of the more difficult components and to sort them out for the group.
The original design is here:
2004 designers site
A mirror is:
The yahoo group is:
I will post images of the build as I progress with mine.
Been having a break from work for last few weeks, just doing the odd bit of consultancy to get stuff done around the house. This morning finished boxing up a 80m/40m SDR TXRX from Tony Parks and now have a 10W PA for it as well (http://partsandkits.com/linearamp.php). Want to give it a go asap but I lost my antenna (tree came down 2 weeks ago and took out vertical and all the antenna supports, no operating from home right now. WX looks interesting for /P this w/e.
Last week finshed a little 20m PSK TCVR off the schematic from KD1JV.
Spent most of last 2 weeks melting solder. In the shack finally clearing much of the un-built stuff, putting the kits and projects together and pairing up things and building them.... I have 5 different little 10W IRF510 et al PA's, one is even SMT and fits in an Altoid tin using a 1U server copper heatsink and fan. Still got lots to build including my version of the NoGaWatt meter that I have a great dual meter from B&O for.
I found in the 'junk' I have plenty of kits to keep me busy for a while...gems are two unbuilt ATS rigs a ATS-III and ATS-IIIB, just completed my NorCal-20 and thinking about what colour to paint it, a second N2PK VNA (big mistake gave first away!), I found I had started and then boxed up a 2N240+ and a BITX20 so restarted them, all the parts for VXCO low voltage valve 'glow bug' CW TX Hans Summers suggested I try, 4 or 5 QRP2004 component kits, G3ROO designed RAMU component set and the tubes for a Nixie Clock for the shack. But the best bit is I finally have got space to work instead of moving jiffy bags and boxes of projects around to find enough space. I do need to build a shelf for the finished projects though. All this in a 10' x 8' shack! Rev George Dobbs or maybe was Dick Pascoe (??) gave me 24 Altoid tins last Rochdale and I have been meaning to use them so I have, 17 of them this w/e contain.. 3 Rockmites, three keyers, a negative voltage (100V) key interface, AF amp and mini speaker, numerous antenna related things, several bits of test kit etc... I could probably make a N5ESE type display, which is what I thought of as I arranged them on a shelf!I just came back into the house to eat after cleaning up the shack and work bench and thought I'd check email.