8-March-2020 Low Bands Microwave contest

After the 2m+70cm March contest I had a spare hour so I gave a few points away in the Low Bands Contest.

On 23cm, my best DX was Brian GM4DIJ/P

20030823

Keith G4ODA was my best DX on 13cm (2.32 GHz).

20030813

The 13cm NoV band, 2.30GHz is a bit of a lash-up. I have to remember to switch the sub-band on the SG-Labs transverter. I had a contact with Keith G4ODA on this band last year. This was my first contact in a contest, with Keith again!

So I worked Keith on three bands.

20030812

2m + 70cm March contest 7/8-March-2020

This didn’t go as well as last year and conditions seemed poor.

On 2m I got a few contacts with stations on the continent and it was nice to work Mark EI3KD again. My best DX was DL0XS at 749 km,  however I must have logged this contact incorrectly, so I got no points for it. Surprisingly, I received a certificate for the highest placed station on 2m using 25W or less.

2003072m

On 70cm I failed to work any continental stations at all, in spite of DF0MU being a good signal. My best DX was G3M at 320 km.

20080770

2003072m_cert

Sony proprietary DC connector pin-out and AC-L10B power adapter fault repair – to power DCR-TRV10E camcorder

This was the label on the underside of the PSU/adapter case:

AC-L10B_underside

 

On the end of the DC cable was a plug that I was not familiar with. I’m assuming this is a proprietary Sony DC connector. I haven’t seen a good picture of this elsewhere, so here is my picture. It has an outer case contact underneath in the picture and two contacts visible. The left contact in the picture carried a nominal +8.4V with respect to the case contact.

Sony_DC_plug

When I first powered up the adapter the output voltage shot up to 12V or so and then gradually died away to nothing. My power adapter had a fault in one of the electrolytic capacitors C108, rated 47uF 35V. It had a slight bulge on the wired underside. C108 is towards the bottom left corner of the picture below:

AC-L10B_PCB_topside

I had no mains lead for this PSU. The mains socket on it was another proprietary connector.

200306_mains_socket

I stripped this and drilled a hole through the connector housing & put an extended grommet through the hole. I fed a twin flex through this & tied a figure-of-eight knot in the flex so that it was secure and would not pull out. I soldered the wires to the board, using the PCB pin holes that the mains socket had been mounted in.  I re-assembled the PSU.

Replacing the capacitor seemed to fix the power adapter, yielding 8.34V to my DVM, no load.

I tested the two other electrolytic capacitors to the rightmost end of the board. C203,  470 uF 16V had a marginal ESR, so might have been heading towards failure. I replaced it with the same value in a slightly chunkier package. C201, 1000uF 16V was OK.