Friday, March 20, 2015

BITX20 - 24. PA part 2... the story continues....

Well, it has been a long while since the 2 criteria to work on the bitx20 both were valid....
A) I have to feel like it....
B) I need time...

But as i have the week off.... i picked up the project box where the Bitx20 is in and opened it up.....
I took out the PA and started to look what was needed.....

I left off here.....





So i grabbed the manual and started to work with the dreaded coils i had to make......
Fortunately I did not have to make trifilar's, just bifilar and singles, which is a lot better.

So after a bit the board looked like this.......

According to the manual you are done at this point.... but i already stated that  the manual is a bit quirky and not 100% correct due to Indian>English>"Dutch understanding" translations.
If you look closely you will see that a 220pF capacitor, 0.55uH coil and a 1N4001 are missing...
Also a 100pF, but you cant see that due to the heat sink being in front of it.
On the top part you see some missing components as well, but that is only if you wanna use a higher voltage on the PA (or actually on the IRF510) then the standard 12 volts. As I intend to use this with standard 12v (or actually 13.8), I choose the other build method described in the manual. few less components.. (diode's resistors and an lm317)

Now getting back to the non explained missing components.........
This is a mod that was allready added to the PCB and also to the parts.... but not so good in the build manual....
In the mod section you find something , but not how to make this L2....
this is the mod:  Bitx20 Linear AMP mod
As it was still not clear what and how to do with L2 (found out later that it was named L2) i downloaded the build manuals of the Bitx20 ver 3b/c.
In there i found exactly what was needed....... 14 turns on a T50-6.
The diode is used in the version 3b/c as well , so i put it in and i have no idea if i should or not.....
I still need to do some testing and do the measuring to see if all is ok....
At least the PA/PSU looks finished now :)





Onto the next part !!! This will be a rebuild of the VFO from test version to something a bit more neat (Has to be done as well as 1 of my cats decide to chew on all the wires.... grrr)  and i will put the VFO and Counter in HF tin enclosures (or whatever they are called in proper English :) .....
Something like this :)


We're getting near something that will actually work!
Untill the next time!

73's
Alex
PA1SBM

Monday, March 16, 2015

K-PO KPS30SW : Part 2 - adding a bi-metal thermal thingie.....

Hello all.....

About the title... As no-one posted a comment about what the proper name was of the temprature sensor, I still call it a "thingie"........

So yesterday i visited my good friend Hans (PD0AC). If you don't know him, you really should look at his blog as well <link>.

We started to talk about my PSU story and I told him about the bi-metal thermal thingie "missing" in one of them..... and he told me that he had "a few" laying around his shack.... (a few seems to mean between 20 and 30) so he gave me one of 60 degrees Celsius... meaning that it will close (make connection) if the temperature exceeds 60c we started to discus the temperature and we came to this conclusion...
  • lower has no use, because it will turn on too often in the warmer summer days
  • lower has no need as the power FET's will be ok till about 120c
  • higher is not needed as 60c is hot enough...
So today i put it in......

Opening this PSU is easy, flip it over and remove 6 screws....


And then you are left with this......


When you take a closer look at the back near the fan, you will see that K-PO has been nice enough to actually leave some taped holes where you can place the bi-metal thermal thingie without a problem..





So after bending the leads a bit for easier soldering , and adding some Thermal paste, i placed it where it should be....


Just a little tip..... the bolts i used were used to mount a floppy disk drive in the good old days...


Now in my opinion this all smells a bit like K-PO trying to reduce manufacturing costs... and let's be honest, i rather have them cut cost in a thermal switch thingy then something significant that can blow up your PSU.... But still, it's nice to have less fan noise in your shack.... 

And again, this in no way a bad PSU. You won't get more bang for your bucks as with K-PO PSU's
And after using them for about 5 years now, i do not believe they will fail anymore due to bad construction or design.


sneak preview: i also bought myself a K-PO SPS30II (which was 59 euro new!), more about that one in a few weeks.... 


73's
Alex
PA1SBM

Sunday, March 8, 2015

CQRLOG 1.9.0 released

On the 4th of March, Petr OK2CQR, released a brand new version of CQRLOG.....

So, what's new, and what bugs were fixed.....
In the download section of www.cqrlog.com we read the following......

Version 1.9.0
  • added support for setting the QTH Nickname in eQSL.cc download dialog (Florian, DF2ET)
  • configuration can be stored into database or local computer only (Preferences -> Program -> Configure storage settings)
  • second directory path to auto backup added
  • Ignore changes caused by LoTW/eQSL upload or download option added
  • CQ and ITU zones are taken from previous QSO if exists
  • added new band map filter
  • CALLSIGN, BAND, MODE, FREQ macros to dxcluster allert command added
  • "Capitalise first letter in QTH field" option added
  • Propagation window improved, now shows more information (Saku, OH1KH)
  • after change of callsign, report, date or time, the QSO was still marked as uploaded to LotW/eQSL - fixed
  • LoTW upload - when Export all QSO was selected, only 500 QSO were exported - fixed
  • buttons caption in CW type window didn't use values from settings
  • online log upload of edited QSO fixed
  • uploading QSO to HamQTH fixed
  • downloading data for web dx cluster fixed

The 2nd new feature, to store your settings in the database is for a single user, in my humble oppinion, the best thing ever.... now you just have to backup your database which contains everything....

I run Linuxmint 17.1, and I installed it in the usual way for me....
Download the new version, and in a shell i run sudo dpkg -i cqrlog_1.9.0-1_amd64.deb
This installed without any problems....
Also running CQRLOG was without any problems... all works as expected so far.....

Again a big thanks to Petr for making this program....

73's
Alex
PA1SBM