Author Topic: vk2seb's channel [Electronics/RF/Reviews/etc]  (Read 4273 times)

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Offline vk2sebTopic starter

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vk2seb's channel [Electronics/RF/Reviews/etc]
« on: July 02, 2017, 02:20:44 am »
[Shameless self-plug for a holiday project that I hope to continue...]
Channel page: here
Website: http://sebholzapfel.com/

(Will update this post with latest installments at the top):

Rapid Prototyping RF Filters with Tape & QUCS



A guide to simulating microstrip filters in QUCS and prototyping them with copper tape on blank FR4 sheets.
These super-cheap materials are good up to a couple gigahertz, as you'll see in the video.
Following a quick real-time demonstration, I simulate and build 2 microstrip filters, a 1GHz stepped-impedance LPF, and a 10GHz end-coupled BPF.


14GHz Mixer Build & Experiments


Building a mixer based on the LTC5548 14GHz MMIC by LT, and a TCM1-83X+ by Mini-Circuits [plus bonus bodge wires ;)]
After measuring LO leakage, conversion loss and IIP3 at different frequencies, I build a poor-man's tracking generator with it.
I also talk (perhaps a bit too much) about HP's old signal identifier feature on my 8555A.
Design files are available at my other web page on this: http://sebholzapfel.com/2-14ghz-mixer-pcb-open-hardware/
An article I did on the PLL is here: http://sebholzapfel.com/14ghz-rf-synthesizer-pcb-experiments/

My other videos so far:

Vintage Crystal Oscillator Teardown & Experiments



In this video I take apart an 80s-era crystal oscillator (yes, might not class as vintage for some of you out there, but it's still older than me  ;) )
I pulled it out of a decommissioned Non-Directional Beacon.
I make some initial frequency measurements before taking it apart, and then after ripping out the crystal I run it through a tracking generator to look for resonance peaks.
Interestingly the crystal seems to operate at a slightly different frequency to what's written on the OCXO packaging, and the 'big' crystal package actually has a small one buried inside. If anyone has any ideas as to why this might be, let me know!

JDS6600 Function Generator Review & Teardown (some may have already seen this as I posted it in the thread for that instrument alongside some more detailed measurements in the TEQ forum)



I take a detailed look at a cheap $100 function generator that came out recently, from JunCe Instruments.
Measuring amplitudes, checking harmonic distortion, making some funky waveforms, and seeing what's inside!
Looking at the 25MHz model in this review.
There are a few things I'd still like to test (PC connectivity and measurement capability for example)

Dumpster Lab PSU Repair (This was actually the first video I tried making so the footage is a bit dodgy in spots where I'm still learning how to use the camera)



I repair an old APLAB ZD3203 DC Lab Power Supply that I rescued from the dumpster.
It had 2 big issues, one with extremely dodgy pots and another with output transients when turning it off.

Please let me know what you think!
Cheers,
vk2seb.
« Last Edit: July 21, 2017, 09:34:23 am by vk2seb »
Projects/Teardowns/Reviews @ YouTube Channel, Musings @ SebHolzapfel.com, Callsign: VK2SEB
 
The following users thanked this post: andyturk, rfspezi

Offline vk2sebTopic starter

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  • Posts: 14
  • Country: au
    • My Blog
14GHz Mixer Build & Experiments
« Reply #1 on: July 07, 2017, 04:22:21 am »
Latest installment...



Building a mixer based on the LTC5548 14GHz MMIC by LT, and a TCM1-83X+ by Mini-Circuits [plus bonus bodge wires ;)]
After measuring LO leakage, conversion loss and IIP3 at different frequencies, I build a poor-man's tracking generator with it.
I also talk (perhaps a bit too much) about HP's old signal identifier feature on my 8555A.

Design files are available at my other web page on this: http://sebholzapfel.com/2-14ghz-mixer-pcb-open-hardware/

An article I did on the PLL is here: http://sebholzapfel.com/14ghz-rf-synthesizer-pcb-experiments/

Let me know what you think!
Cheers,
vk2seb.
Projects/Teardowns/Reviews @ YouTube Channel, Musings @ SebHolzapfel.com, Callsign: VK2SEB
 

Offline vk2sebTopic starter

  • Contributor
  • Posts: 14
  • Country: au
    • My Blog
Rapid Prototyping RF Filters with Tape & QUCS
« Reply #2 on: July 21, 2017, 09:33:30 am »
Latest installment... (finally! this one was more work than I expected..)



A guide to simulating microstrip filters in QUCS and prototyping them with copper tape on blank FR4 sheets.
These super-cheap materials are good up to a couple gigahertz, as you'll see in the video.
Following a quick real-time demonstration, I simulate and build 2 microstrip filters, a 1GHz stepped-impedance LPF, and a 10GHz end-coupled BPF.

It's for videos like these that I wish I had better equipment  ;)

Let me know what you think!
Cheers,
vk2seb.
Projects/Teardowns/Reviews @ YouTube Channel, Musings @ SebHolzapfel.com, Callsign: VK2SEB
 
The following users thanked this post: mswhin63

Offline albert22

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Re: vk2seb's channel [Electronics/RF/Reviews/etc]
« Reply #3 on: July 21, 2017, 04:45:27 pm »
A lot of interesting and useful info in your videos. Their are GREAT!!  :clap:
Particularly the last one on microstrip filters.
Didnt know about Qucs, I am going to check it.
thanks & regards
 

Offline vk2sebTopic starter

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  • Posts: 14
  • Country: au
    • My Blog
Re: vk2seb's channel [Electronics/RF/Reviews/etc]
« Reply #4 on: July 22, 2017, 08:55:03 am »
Quote from: albert22
A lot of interesting and useful info in your videos. Their are GREAT!!  :clap:
Particularly the last one on microstrip filters.

Cheers albert22! Means a lot :). I did hope that they would be useful to someone.

Quote from: albert22
Didnt know about Qucs, I am going to check it.

Yeah it is a bit of a hidden gem, I discovered it and the synthesis tools when I was reading through this book, it's used in a lot of the worked examples.

Cheers,
vk2seb
Projects/Teardowns/Reviews @ YouTube Channel, Musings @ SebHolzapfel.com, Callsign: VK2SEB
 
The following users thanked this post: albert22

Offline ahakman

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Re: vk2seb's channel [Electronics/RF/Reviews/etc]
« Reply #5 on: August 20, 2020, 02:33:29 am »
What ever happened to your channel / blog vk2seb? I re-discovered your copper tape filter video today, which I remember watching a long time ago (before I had a VNA) and was really excited for more excellent content, but there hasn't been anything new in a long time.
 


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