First Test - Poor Results

Discussion about this major DATV Project. See https://wiki.batc.org.uk/The_Portsdown_Transmitter
Nick
Posts: 121
Joined: Sat Oct 03, 2015 10:09 am

Re: First Test - Poor Results

Post by Nick » Fri Feb 02, 2018 11:51 am

The low power output via the RF Switch has been sorted. It was all due to R01 on the RF Board. A close inspection showed a poor soldered joint on the side to pin 10 of ADG904.

After resoldering this the power output on 23cms went up from -23dBm to +3dBm.

Must check more carefully in future. :oops:

G8GKQ
Site Admin
Posts: 2812
Joined: Sun Mar 22, 2009 1:21 pm

Re: First Test - Poor Results

Post by G8GKQ » Fri Feb 02, 2018 12:04 pm

Hi Nick

Pleased to hear that you have sorted that issue. Sounds like you might be ready to transmit. Have you anyone local enough to try the Portsdown barefoot on-air, or will you be building linears next?

Dave

Nick
Posts: 121
Joined: Sat Oct 03, 2015 10:09 am

Re: First Test - Poor Results

Post by Nick » Fri Feb 02, 2018 6:19 pm

Hi Dave,

Unfortunately there is no one near so I will have to get on with the amplifiers. I have Mitsubishi 60W modules for 2mtr and 70cm for the amplifiers and also got G4DDK preamps to make, so got some work yet. The nearest station to me must be Rob - M0DTS who I met up on the moors during one of the activity weekends.

With my location being where it is I expect my best results will be on 70cms and 2mtrs. Out of interest I had a look through my old logbook and noted that the first TV contact I had was on 70cms on 31st March 1981. This was of course B&W from an old Philips camera using (I think ?) a Microwave Modules transmitter. Things have moved on a lot since then.....

Nick - G4NKV.

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