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Old 9th June 2018, 09:23 PM   #271
w5jag is offline w5jag  United States
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Not the greatest, but should be legible:
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Old 9th June 2018, 10:10 PM   #272
haiqu is offline haiqu  Australia
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OP: In Melbourne it's worthwhile tuning in to Crossband Radio, which has been in operation around 40 years on the ham bands. They've skirted the law and played cat-and-mouse with the radio inspectors for most of that time. Most 'taining indeed. You can find recordings of some of their older 'missions here:

ONE SIXTY METER CROSSBAND RADIO
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Old 9th June 2018, 10:19 PM   #273
haiqu is offline haiqu  Australia
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In New Zealand I met an old pilot called Bob who spent many years doing parcel deliveries to tiny Pacific islands. At one stage he was semi-retired and decided to set up a pirate radio station on the island he was living on. Before every raid he would get word that there was an inspector arriving, just in time to shift the antenna to a different tree.

But Bob got bored and when he heard of a new arrival who owned a nice little French airplane he decided to make a new friend in the hope of getting a bit of flying in. After establishing his flying credentials the owner was happy to let Bob take it up, and elated he shot off into the sky and familiarized himself with the controls. The little plane handled quite differently than Bob was used to and was quite slick, so he spent a fair bit of time doing simulated landings at altitude to ensure he wouldn't overshoot the island's rather small runway.

About this point he realized that he had lost sight of the island. Looking at the gauges and instruments he also realized that most of them were in French, and that navigating back to his point of origin was going to be trickier than expected. After considering his plight for a while he struck on a solution. He retuned the radios to pick up his pirate radio station and used it as a homing beacon.

True story.
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[VK9VK] With great power comes great current squared times resistance.
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Last edited by haiqu; 9th June 2018 at 10:22 PM.
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Old 11th June 2018, 03:16 AM   #274
w5jag is offline w5jag  United States
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I put the tuned circuit at 54 MHz, and it would not oscillate. I didn't try very hard to make it work, since I have more crystals ordered.

This particular chip will oscillate all the way down to 2.3 VDC, and achieves maximum output at 3.0 VDC. The second harmonic stays at -44 dB, and frequency remains constant regardless of voltage.

The screen captures are at 3.0 VDC.

Win W5JAG
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Old 13th June 2018, 11:35 AM   #275
Rodeodave is offline Rodeodave  Austria
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No RF gear here?
Hi, I don't really know where else to post this. I still have this RF stack lurking in the basement:

Boonton 202E Signal Generator, Univerter 207-EP and the 202EP Power Supply.

Could this be of any interest to anyone?
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Old 13th June 2018, 04:05 PM   #276
anatech is offline anatech  Canada
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No RF gear here?
Wow, is that ever cool!

Don't throw it out. Some museum might want it for display, or a HAM club.

-Chris
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Old 13th June 2018, 04:40 PM   #277
Rodeodave is offline Rodeodave  Austria
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No worries, I've been holding on to it for several years now, with no intention to scrap it. It's just like it came from the lab, didn't even pop the hood.
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File Type: jpg 20180610_172109.jpg (993.3 KB, 76 views)
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Old 13th June 2018, 05:23 PM   #278
anatech is offline anatech  Canada
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No RF gear here?
I think it's wonderful. What a beautiful link to the past when this was probably cutting edge stuff.
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Old 18th June 2018, 05:18 AM   #279
w5jag is offline w5jag  United States
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J310 JFET times two, emulating the dual gate 40673 MOSFET, in SMD format, the exception being the flying 1/8 watt 100K resistor to bias the gate of the upper JFET.

The load is a generic 10.7 MHz crystal filter. I am using a 60 MHz "FeelTech" FY6600 waveform generator as the LO. Looks like about 6-7 volts peak to peak is about the right LO drive level for this circuit.

Subjectively, the J310's seem hotter and quieter than the 2N3823's. The reduced footprint of the circuit is substantial, although the leaded / perf version could be made smaller than it is now.

It is going to take a bit of practice to get proficient with the SMD parts. There were certain parts of the circuit where 0603 might have been easier to work with than the 1206 parts.

Win W5JAG
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Old 21st June 2018, 05:19 PM   #280
w5jag is offline w5jag  United States
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Another flash sale on eBay right now through this evening, for anyone interested .... $15 off a cumulative $75 purchase, applies to anything. I see about $75.01 worth of SMD components / stuff in my near future ....

Since I am starting SMD ab initio, I have decided the "sample book" small notebooks, and filler sheets to be a reasonable way to store the bulk of the parts, and is a convenient way to help build an inventory fast, so that is the road I am headed down - mostly 1206, some 0603.

Have both the first and second mixers built out in dual J310 SMD, HF => 45 MHz => 9 MHz => FT-817 using the FY 6600 as the LO's - it is not spectacular as an RF generator, but usable. It is easy to set a frequency, and useful to have a variable output voltage. The one I have is rated for a 60 MHz sine wave, and it will do that, but amplitude drops in the low VHF range. 5 volts is all it will do at 46 MHz. It wasn't expensive at all, and I got it for 20% off at that, so not complaining - it actually looks to be quite a bit of kit and has a surprisingly good manual. Takes up almost no space, comes with cables.

Some SMD inductors and more crystals showed up today, and it's been interesting playing with the crystal stuff, particularly the LM375, but I am seriously considering just getting one of those 54 MHz VCXO Crystek lumps for the 2nd LO and being done with it. Use what's been learned for a new crystal BFO. If the Crystek is good enough for mobile EME, it should work fine in the trunk of my car.

May build an unneeded vacuum tube something for a break before I plow back into this. I think this is the longest I've ever spent on an uninterrupted single project, with really nothing to show for it.

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