#151

RF Sampler test with 10 and 35 Watts and on a spectrum analyzer.
LTDZ 35-4400 go.tonyalbus.c...
LTDZ 35-4400 go.tonyalbus.c...
NanoVNA-H4 go.tonyalbus.c...
NanoVNA-H4 go.tonyalbus.c...
TinySA go.tonyalbus.c...
TinySA go.tonyalbus.c...
RG316 Cable BNC-BNC go.tonyalbus.c...
RG316 Cable BNC-BNC go.tonyalbus.c...
RG316 Cable SMA-BNC go.tonyalbus.c...
RG316 Cable SMA-BNC go.tonyalbus.c...

[@DavidJohnstone-hi9kr]

Thanks for the two great videos on this device build. I'm not going to build one based on your results. I really think the wire-wound pot is causing the non-linear response, unless it's a non-inductive (which I haven't ever seen). I have a -50db sample element for my Bird 43, which I'll continue to use. Yeah, it's not as compact as your multi-purpose build. Keep up the good work ! 73 Dave

[@TonyAlbus]

Hi Dave, yes the variable one with the pot, will not be in my future product, but the fixed resistor test was very good, very flat response. The Bird will be best always :) .. 73 Tony

[@johnnz4375]

Those random dips, maybe it's the wirewound pot it's technically an inductor.

[@TonyAlbus]

The resistors only are super flat.. thats what i am using now.

[@dennisqwertyuiop]

Great demo of your new sampler,I have several,one wiith demod output to se mouladion on scope,you can easy and it to your box

[@TonyAlbus]

Thank you Dennis! yes that is also a nice idea..

[@mrbambix]

your right that would be a nice addition how would you propose to add it to the box Tony build Dennis?

[@hobbyrob313]

Ik heb al weer gezien ik heb veel te snel geoordeeld!
De andere video nu ook gezien. ( met potmeter gaan we niet doen dus! )
VrGr Rob

[@TonyAlbus]

Je de vaste weerstanden zijn veel vlakker, de pot gebruik ik eigelijk ooit.

[@arkinzoodsma1510]

nice stuff!

[@TonyAlbus]

Thank you!

[@craxd1]

Place a piece of aluminum heatsink under the resistor on the box, and that should up the time that you can use it.

[@TonyAlbus]

Thanks, the housing being aluminum i thought i just did that. but axtra radiation of heat is allways better

[@craxd1]

@@TonyAlbus See if you can locate a finned piece off of a PA from a radio or mobile amp. Put some heat compound on it, and mount that to the box. That should take the heat away just as it would on a PA transistor.

[@TonyAlbus]

@@craxd1 Thanks!

[@lmamakos]

@@craxd1 You can take a cue from other applications, and maybe sand and polish the cast aluminum and the bottom of the resistor to improve the contact. The heat-sink goo has better thermal conductivity than air and good for filling tiny gaps, but robust metal to metal contact would be even better.

[@aacmckay]

I see in your notes that the pot in the variable attenuation port was wire-wound. I suspect that may be a big portion of the cause of the poor behaviour of that circuit. Try finding a carbon or metal oxide film potentiometer instead. Though I'm not sure what the dissipation requirements of that part are off the top of my head.

[@TonyAlbus]

Thanks, i am just using the fixed 40dB as it is near flat.

[@acestudioscouk-Ace-G0ACE]

Thanks for the two videos about this, it's been very informative and useful. I have need of this type of unit, so may build something similar. The standard design which you have seen on RUclips was originally a Wes Hayward design and featured in QST magazine. You can see a version here: ruclips.net/video/fKPG1FWcB5c/видео.html Best 73.

[@TonyAlbus]

Thanks!