BATC Forum

The TS352 allegedly uses the Skyworks SE5004L amplifier chip, which should give 400mW linear output when driven by a Pluto. Gearbest are doing this with an RC305 receiver for £13.08 delivered.

Brian


https://www.gearbest.com/fpv-system/pp_218697.html

. . . and now out of stock.

My TS352 (Ebay 262706030579) has arrived and does contain the preferred Si5004L 400mW amplifier chip. Someone else has received the TS352 I showed in my CAT17 presentation from DX.COM, but it contains an RTC6659 which gives 200mW. Another transmitter (Ebay 391732465571) shows an Si5004L chip in the photo. One has been ordered.

I've modified my TS352 to attach the Pluto and it is giving significant gain. I'm sure someone with steadier hands could do a better job. I hope to measure it if I can borrow some better kit at the weekend. There was significant feedthrough from the analogue modulator - the unit was transmitting analogue on 5665MHz and digital on 5763MHz at the same time. The modulator was disabled by removing a tiny resistor.

Brian

The 5.8 GHz PA shown below includes 2 SiGe 5004L gain blocks after an input attenuator - presumably to take the 600mW typical input down to a reasonable level. The voltage regulator is an MP1584 - as used in the smaller eBay buck downcoverters.

Datasheets: http://www.skyworksinc.com/uploads/docu ... 02393B.pdf
https://www.monolithicpower.com/Portals ... 4_r1.0.pdf

These PAs are very sensitive to output SWR - as I found out to my cost this evening. Whilst testing a new RP-SMA to SMA adaptor, it clearly was not done up tight enough, and there was a green flash and magic smoke from the PA. Both RF Gain blocks and the buck regulator diode blew up. Hence the lid-off photo!

Dave, G8GKQ

I don't know how reliable an indication it is, but G0EID's TS352 which doesn't have the Si5004L PA chip has red wires connecting top to bottom. The ones I have with the Si5004L have multicoloured wires.

Brian

I measured the power output of the modified TS352 when driven by a Pluto.

MHz mW
5500 110
5600 120
5700 80
5800 30

The drop off is dramatic above 5700MHz, which is where I want to use it. The Pluto itself only drops a dB or so. I'll try to measure the analogue output of an unmodified one if I can find the correct attenuators.

The Pluto itself was only outputting 0.1mW, so 1mW would give nearly the maximum linear output of 400mW even above 5700MHz. Charles said there were several gain adjustments in the Pluto, so maybe that will come.

Brian