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Re: Low Band QRP
@ KI4IO:? Yes, agree 100% that on 160, it's all about the antenna. But I think your particular inverted-L is a bit higher up in the ranks than you might think. In 2017/2018, when the ionosphere was
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Kirk Kleinschmidt, NT0Z
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#9543
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Re: NC40A ON 160
Howard,
Though the thought of building an "NC160A" would be poo-pooed in some quarters, because I needed an excuse to warm up my iron, I purchased a 160m 1Watter from Diz, and it resulted in a nice
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k6whp
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#9542
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Re: Low Band QRP
The price of admission for 160 is an efficient antenna.? I'm probably at the low end with a 165' inverted-L up 75' with 47 mixed length radials from 15 to 70'.? I use a K2 at 5 Watts.
I like the
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Gerald Wolczanski
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#9541
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Low Band QRP
As AA7FO mentioned this matter, here is what I can share.
On 160m I have had several CW QSOs with folk operating simple tube transmitters at 5 to 10 watts. ?So it¡¯s definitely viable during the
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Curt
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#9540
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Chinese PCB's
In response to AF7KR's question:
"Speaking of boards. ?What is going to be the economics now of getting
PCBWay or other boards from China? "
Here's a link to JLCPCB's FAQ about
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hwstar
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#9539
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Re: f_T fixture and cheap transistors [long]
Here it is:
https://github.com/3ym3ym/fT_jig
73, Mike AF7KR
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vbifyz
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#9538
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Re: ADC Project Status, Fake Parts, Varactor Diodes and then Chinese Critter Checker[long]
Chuck
I had a similar experience to your fake FET's except mine were fake BF245A's. I got a refund by sending a picture of my component tester's BJT display. The generic NPN's that they had sent seem
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Mark Dunning
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#9537
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ADC Project Status, Fake Parts, Varactor Diodes and then Chinese Critter Checker[long]
Delayed in getting to build second ADC xcvr prototype because a package of J310s has
gone across the country and back for more than a week and having trouble
getting to me.? Hopefully by Monday.?
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chuck adams
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#9536
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Re: NC40A ON 160
I quick look at the AE marketplace reveals ample supplies of 4MHz crystals.? That with a 2-to-2.2MHz VFO would tune it down to the 160M band.? There is also a 4.433MHz HC-49s crystal offer, but 3x
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[email protected]
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#9535
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Re: NC40A ON 160
Howard
you have a fantastic idea. Avoid an IF that is a multiple of 1.8. Sounds pretty easy. While TR signal should work I wonder if it might carry transmit RF leakage? ?You may have to experiment
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Curt
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#9534
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NC40A ON 160
Good morning, all.? I'm thinking about a 160M build using one of my leftover NC40A boards.
I actually only need the receive side but with a bit more work can eventually get a complete transceiver.?
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[email protected]
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#9533
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Re: QRP TX LPF illustration (30M built)
Also if you notice I widened the sweep this time to include the 4th harmonic which shows up about the same level as the 2nd harmonic. I imagine the other filters show the same for the 4th harmonic.
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Steve Ratzlaff
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#9532
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Re: QRP TX LPF illustration (30M built)
I built the 30M W5USJ LPF from the chart, next. You'll notice on the chart that the input and output impedances for this filter are close to 50 ohms with little differences. My tests showed the
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Steve Ratzlaff
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#9531
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Re: QRP TX LPF illustration
Hi,
A while back, I noticed the familiar double-pi filter circuit that¡¯s often used at output of transmitters. One day, I did some calculations and realized the connection between the values of L
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mangrove
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#9530
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Re: QRP TX LPF illustration
Hi Goody,
I built the W5USJ 80M LPF from the chart just now and tested it; I used T37-2 toroids, 22 and 23 turns, inductances set with the DE-5000 LCR meter, silver mica caps except polystyrene for
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Steve Ratzlaff
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#9529
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Re: QRP TX LPF illustration
Hi Steve,
Thank you for the information! I was wondering how one designed these as I
wasn't finding any direct design tools online. The chart will be enough to
get me started; I'll build it and do
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Anthony Good
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#9528
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Re: QRP TX LPF illustration
Wow that is an amazing difference!? Next time I need one I will try to use this.? Sounds like the design is a bit more involved though.
Thanks!
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bruce williams
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#9527
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Re: 1W and 5W build guides
8 have never seen the videos and would appreciate if they were available again!
Thanks ?
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bruce williams
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#9526
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Re: How good is the 1N4004 diode as a varactor
Like Dave mentioned, there is info in the old qrp group from the 25th anniversery NC-40 build...
Here is what I wrote (message #14308):
"I am running a 1n4007 in mine, works great.
I am using Chuck's
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wb6ogd
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#9525
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Re: How good is the 1N4004 diode as a varactor
If anyone has a project that needs an MV209 (40pF at 1V to 10pF at 9V) or an MV2101 (10pF at 1V to 5pF at 9V), I have some extras. But to be clear I'm not moving them from my spare stock to your spare
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Tom - VE3PSZ
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#9524
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