SBS-1 & SSE 1090SJ any experience with a preamp?

[jakems]

Thanks Tom and Anmer, I will indeed email Jim.

[north borneo radar]

Thanks Tom and Anmer, I will indeed email Jim.

Hi, just curious, what feedback did you get from Jim regarding adding a preamp to the antenna? many thanks.

[jakems]

Hi.

I emailed Jim on 20 January and I have not had a reply yet. If I hear from him I will post details of his reply here.

[Chris-G0WTZ]

Jakems when you got the pre aamp did it not have an N-N patch cable?

If not email me and I will first class post one tomorrow

Regards

Chris

[jakems]

Just to update those who offered helpful comments. Firstly I found there are two types of aerial, the one Chris sells is open circuit, the SSE 1090SJ I have is short circuit. The preamp has two relays in it which require energising before the preamp is put inline. With a short circuit aerial the relays never energise, the power supply is being shorted. I found that if at the aerial end the aerial cable was disconnected the relays brought the preamp inline and then when the aerial was reconnected it worked perfectly. The maximum distance I picked up aircraft as measured by SBSplotter went up from around 150NM to over 200NM, the number of flights sent in the AD daily report went up from around 4,500 to nearly 6,000, so it was very worth while. Unfortunately if I had to get on the roof every time it needed power cycling it was just not viable. A friend of mine who is an electronic engineer said a capacitor inline with the output would solve the issue. I asked Chris about this and he said the manufacturer said it would not work. Anyway we took the risk and added a capacitor and all is well. The one thing I did notice was I ran with the preamp next to the bias-t and SBS for a couple of weeks, then when I moved it up on the roof the range and flight count did not really change. Maybe the Westflex 103 cable shields the signal well.

[Anmer]

I've had reports of something similar and I also exprienced this when I did the review of the Kinetic kit.

Whose preamp did you use?

[Chris-G0WTZ]

Mike he bought the preamp from me
I have tried several makes and none seem to like a shorted antenna

I have just got  a new pre amp in but yet to test it

Regards

[Truetrack]

Thanks Steve for posting the outcome at yours
good to hear that blocking the DC by a capacitor solved the issue of disceonnecting and reconnecting
the preamp.
As Chris already put it various preamps showed the same behaviour.

Many types of antennas have elements shorted to GND just like the SSE 1090SJ, similar the folded element in
GP and Triple legs, or the Sleeve Vertical , all widely used in commerical/industrial/public services.

Is it not strange that they then seem to prevent the use of some preamp types ?

[north borneo radar]

very interesting findings Jakems and thanks for sharing your findings. definitely learnt something new from this...

[Chris-G0WTZ]

What value capacitor did he use and what type I will give it a try

[jakems]

100pf, track cut beneath the capacitor.

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[vortex60]

Have got a pre amp attached to GP-1090 Outdoor antenna 1090MH and is worth laying out a few bob......can recommend it...be aware that you do need a power supply for the unit...........Rgds vortex60