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Re: Norcal 40a Toroids
Hi Paul, Yes, you can measure your torroids. What I do is put the filter together on the PCB and sweep it using my PHSNA (poor ham's scaler network analyzer). Did my xtal filter too. See attached (I
By wb6ogd · #510 ·
Norcal 40a Toroids
I'm building a Norcal 40a and wondering if the toroids can be measured and verified prior to installation. I have an LC meter sitting here on the bench. Thanks. Paul VA3ZC
Re: Measuring Resonant Frequency of Traps
Gents, Absolutely great! Thanks for these suggestions and links! If this does not drag them out of Baofeng "Tech-hood" nothing will. -- William, k6whp -------------------- "Cheer up, things could get
Re: Measuring Resonant Frequency of Traps
This little noise generator would work fine: https://www.radiohobbyist.org/blog/?p=1884 -- Dale Hardin Elberta, AL
By Dale Hardin KS4NS · #507 ·
Re: Measuring Resonant Frequency of Traps
I second what Dale says, however (since measuring traps is the subject),? a simple noise generator along with a receiver can be employed to measure traps.? Example: < https://youtu.be/kuDkdrI4bBc (
By sigcom1 · #506 ·
Re: Varactor Diode C Measurement
Chuck, On page 16 of http://transport.ece.illinois.edu/ece340f12-lectures/ece340lecture27-junccap.pdf there's an equation for the capacitance of a reverse biased diode Cj =? ?A/2 *
By Jerry Gaffke · #505 ·
Re: Measuring Resonant Frequency of Traps
Don't forget the "noise bridge".? Here is a simple one that can be built out of junk parts: https://www.radioexperimenter.us/rm-1996-05/antenna-noise-bridge-detector.html It is a very useful and
By Dale Hardin KS4NS · #504 ·
Re: Varactor Diode C Measurement
Gary,? What was the specified part? -- Chuck, W5USJ (ex K2OFN) Point, Rains Co, TX? EM22cv
By Chuck Carpenter · #503 ·
Re: Varactor Diode C Measurement
Jerry, the shape of the curve in fig 3 is typical of?junctions of non?"purpose built" diodes. (like that term). I've attached a set of curves from K7QO.? The curve at the bottom is a power diode.?
By Chuck Carpenter · #502 ·
Re: Measuring Resonant Frequency of Traps Newbies SSTV
Tangential note and thank you to Ray for enabling the "edit" feature for comments. Sure allows one ot revise embarrassing spelling errors and grammatical mistakes. Never did understand why Chuck did
By k6whp · #501 ·
Re: Measuring Resonant Frequency of Traps Newbies SSTV
Rob, Understand that. I coined the term "Baofeng Tech" -- originally defamatory -- mainly because there were a number of guys on a local SoCal repeater system who occupied commute time talking on
NanoVNA for Network Measurements
This is one of the great tools now available to all?for working with? project that you pump and signal into or receive a signal from?and finding out what is really going on.? The 11, 12 ports can
By Chuck Carpenter · #499 ·
Re: Measuring Resonant Frequency of Traps Newbies SSTV
I don't know about you guys but when I first got a Technician license 21 years ago (after passing 5WPM CW) and I was finally allowed to use a 2 meter HT I could not purchase a 2 meter HT for anything
By Rob <roomberg@...> · #498 ·
Re: Si5351 output power
Loading the clock outputs with 50 ohms (such as a 6db attenuator) will make crosstalk and phase noise much worse. Hence the discussion here of cheap 74ACT and 74LVC series buffers to drive a 50 ohm
By Jerry Gaffke · #497 ·
Re: Measuring Resonant Frequency of Traps
It's a Military/Viet Nam Era thing. "F---ing New Guy" meaning the newest arrival in a unit. Also, many, many thanks for the great ideas. I think with the availability and affordability of the antenna
By k6whp · #496 ·
Re: Measuring Resonant Frequency of Traps
whats the FNG mean?
By Rob <roomberg@...> · #495 ·
Re: Measuring Resonant Frequency of Traps
NOTHING beats a real antenna analyzer. Just my opinion. I bought a used MFJ259 for $100 ....twenty years ago and it has been THE "go to" tool for the local radio club and has been passed around so
By Rob <roomberg@...> · #494 ·
Re: Si5351 output power
Hi Yes, generally it is a good idea to make the mixer see a constant load vs frequency. So a 6 dB pad will provide a higher return loss than 3 dB will. But given that the output power from a single
By Bo, OZ2M · #493 ·
Re: Measuring Resonant Frequency of Traps
A Millen Antenna Bridge will give you both the R and Xc of an antenna. But a simple Heathkit Antenna Bridge will give you only the R of the antenna. These things date WAY BACK! And they have only
By Bob Macklin · #492 ·
Re: Measuring Resonant Frequency of Traps
Some newer transceivers, like the Icom IC-7300, include a graphical SWR plot function. Put a dummy load on the other end of the trap and have the radio show you the swr plot. That might help some.
By Michael Maiorana · #491 ·