Monday, November 25, 2019

Post mortem of WIA Spring Field Day Contest 2019

Roger VK2ZRH  and myself operated an  8hr section of the contest from Gowan QF46pu, which is n.w. of Bathurst in NSW. On a hill at 920m ASL.
We took gear to cover 6m, 2m, 70cm, 23cm, 9cm and 3cm, all yagis for 6,2,70,23  and panel for 3.4GHz and dish for 3cm. 
We chose this location on basis of working local microwave stations of VK2CU and VK2DAG who have all bands up to an including 122GHz versus trade off of operating back towards Sydney to pickup on stations on the low bands from Sydney and coast.
We had a few contacts on 6,2,70 with various locals from Central West ARC, but the long distance contacts we hoped to get didn't happen,  eventhough we receiving fhe VK4RHT Atherton Tablelands 52.280 beacon coming in solid for hours, plus hearing VK2RWI Dural 2m, 70cm and 23cm beacons, which proved antennas are working, we just didnt hear anything.
What i learnt from this is we just can't try and work everything, its either go to Gowan to work microwave bands, or locate closer to Sydney for the contest, i.e. up in the Blue Mtns, i think it better do special trips to Gowan just to do microwave activity,such as MAD 23 on 23 days and operate from different hills to test our abilities at operating microwave portable. On side note, one of the locals from Central West, Doug VK2XLJ operated portable from Mt Canobolis and worked a ZL on 2m SSB as part of the contest, thats pretty impressive as tropo path from ZL rarely extends inland or over the Great Dividing Range.

Friday, November 8, 2019

Converting Codan 8528 Remote Head backlighting from globes to LEDs

I noticed the remote head for my Codan 8528 HF xcvr getting, ... is hard to see at night, i thought maybe a globe blown, so opened it up and removed the pcb to see where the globes are for front panel key backligting. Well, surprise all the globes are working when plugged in on the bench. I thought, well, they going to fail one day and they work poorly as us, so let's see about making it better. 

Made some measurements  across globes solder pad, running about 4.3volts across globe, that's an odd number,  did more checking to find they running three globes in series.  Checking globes behind LCD display shows six globes.  This means three sets of three globes, if one fails, you lose a good part of your backlighting.

Next what can we replace these with, I have some rolls of LED strings, I tried some blue, but poor backlighting of the keyboard, found white LED  giving best keyboard backlighting., same for the LCD display, which yellow backing.

Next cut some strings of  white LED ribbon and connect to the 12v and gnd points on the board. Removed old globes.  Now Codan remote head  much better at night. I will document on my web pages sometime.

Wednesday, November 6, 2019

Spring 2019 VHF UHF SHF Field Day Contest discussion forum

If you intending to operate in the upcoming contest 23rd, 24th November, 2019, then add your operating details in this discussion forum to maximise activity

http://www.vklogger.com/viewtopic.php?f=31&t=13975&p=63877#p63877