vk2seb's channel [Electronics/RF/Reviews/etc] - Page 1
Forum section: electronics / general

author: vk2seb
author_rank: Contributor
timestamp: July 02, 2017, 02:20:44 am
content: [Shameless self-plug for a holiday project that I hope to continue...]Channel page:hereWebsite:http://sebholzapfel.com/(Will update this post with latest installments at the top):Rapid Prototyping RF Filters with Tape & QUCSA 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 & ExperimentsBuilding 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 & ExperimentsIn 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.

author: vk2seb
author_rank: Contributor
timestamp: July 07, 2017, 04:22:21 am
content: 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.

author: vk2seb
author_rank: Contributor
timestamp: July 21, 2017, 09:33:30 am
content: 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 equipmentLet me know what you think!Cheers,vk2seb.

author: albert22
author_rank: Regular Contributor
timestamp: July 21, 2017, 04:45:27 pm
content: A lot of interesting and useful info in your videos. Their are GREAT!!Particularly the last one on microstrip filters.Didnt know about Qucs, I am going to check it.thanks & regards

author: vk2seb
author_rank: Contributor
timestamp: July 22, 2017, 08:55:03 am
content: Quote from: albert22Cheers albert22! Means a lot. I did hope that they would be useful to someone.Quote from: albert22Yeah it is a bit of a hidden gem, I discovered it and the synthesis tools when I was reading throughthis book, it's used in a lot of the worked examples.Cheers,vk2seb

author: ahakman
author_rank: Regular Contributor
timestamp: August 20, 2020, 02:33:29 am
content: 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.