Hi Gordon,

Glad you are feeling better. I'm looking forward to your results.

On a side note, I don't have a second quality receiver to use so I'm going to try to see if I can concoct a spectrum analyzer from a RTL-SDR dongle. I have no idea how accurate any purported DB levels from any dongle/SDR software will be, so I've been looking around for a step attenuator to buy or build.?

I ran across these amazing (and inexpensive) things.??don't know if they may be of any help to you making your measurements. Ordered a couple from Digi-key and they came in a few days.?

In my case I'm going to use two of them (plus an voltage divider like you described) to get a 60+ DB adjustable attenuation range to attempt to calibrate my dongle/SDR and to step the attenuation back down to match the fundamental to get more accurate harmonic measurements. I may need a microscope to solder wires to them, dead bug style. The big issue that will likely need a solution will be the dongle, unlike a ?good receiver, will likely overload on fundamental when I reduce then attenuation to measure the harmonics. Won't know until I try.

Tom, wb6b

Tom

When you measure VSWR you are measuring reflected power. The less reflected power, the lower the indicated VSWR. When you measure a transformer (or attenuator, or feedline, or any circuit element) with 100% loss, there is no measured reflected power. All of the forward power is absorbed by the circuit element and none is reflected. A VSWR bridge sees no reflected power and reports VSWR = 1:1.

WA8TOD

While I agree the only way to measure the effectiveness of a transformer (either an antenna "matching" transformer or the transformer used to couple the output of the transmitter PA to the antenna load) is to measure the power in vs power out. Either by coupling two back to back, or simply measuring the RF voltage on the input (with a carefully calibrated 50 ohm input impedance driving the transformer [transmitters do not magically have 50 ohm output impedances. A 90% efficient transmitter will have a very low, maybe a few ohms, output impedance, for example]) vs the output with the intended load impedance and calculating the power in and out. Also in both the case of antenna and PA transformers, the power level and reactance of the load will be a factor; putting outer limits on how high the SWR can be and power handling. Transmitters successfully use transformers all the time, so I imagine antennas can also.?

However, why would a transformer with 100% loss have an SWR of 1:1. Why would a transformer with 100% loss end up with an impedance of 50 ohms, rather than some other value, like 100 ohms, 500 ohms, 10 or 20 ohms?

Tom, wb6b

Well, I'm several days BEHIND on what I had planned on this project, but I have some baseline results finally.? ?(Had pancreatitis last week and gallbladder removed Monday and laid up a bit, then struggled several days with an open-repeater ics-ctrl repeater controller raspberry pi project to completion).

First goal was to develop a homebrew measurement lab in place of a spectrum analyzer, to allow baseline measurements of harmonic output from a stock ubitx v3/4.? ?(Prior to modification to add in a daughterboard filter relay repair described previously.)

Using a 50 ohm/16.6K ohm voltage divider built on top of a Heathkit cantenna ( 2 100 ohm in parallel to make the 50 ohm, checked with very low SWR well beyond 30 MHz on antenna analyzer to be sure not wirewound resistors) and 6 100K resistors in parallel to make the top of the voltage divider), created approximatelly 50 dB attentuator.

Then double shielded BNC coax patch cord to selected bnc attenuator right at the input to an ICOM 718 receiver.??

Tonight was initial tests.? ?First problem:? V4.3 of software would not go into CW mode no matter what I tried on the key terminals.? ?Finally gave up and reverted to my own modified v2.0 of the ubitx code which does transmit.? ?Next problem was my radio shack "wattmeter" indicates rather low outputs.....but may not be accurate at all so I just went forward.

"Attentuator" is the ADDITIONAL attenuator beyond the estimated 50 db at the cantenna.

Mode? ? ? ?Freq? ? ? Meas.Watts? Attenuator? ?Fundamental? ?2nd Harmonic? ?3rd Harmonic? 4th Harmonic? ?5th Harmonic
CW? ? ? ? ?3.505? ? ? ? 2? ? ? ? ? ? ? ? ? 20 dB? ? ? ? ? S9+25? ? ? ? ? ? ? ?S8? ? ? ? ? ? ? ? ? ? ? ? S8? ? ? ? ? ? ? ?not meas? ? ? ? ? S8
CW? ? ? ? ?7.080? ? ? ? 1? ? ? ? ? ? ? ? ? 20 dB? ? ? ? ? S9+25? ? ? ? ? ? ? ?S6? ? ? ? ? ? ? ? ? ? ? ? S8.5? ? ? ? ? ?not? meas? ? ? ? ? not meas


All I have is the little LCD screen of the ICOM 718....but the readings were quite steady and the tuning in of the signal was not critical at all.?For the very first crack at? this EVER in my life, I was much more impressed with the measurement setup than I was with the problems I was inhaving the little uBitx to perform for me to allow testing.? ? I'll fiddle with this a bit more to be sure I'm happy with some baseline readings before I begin hacking traces and building the circuit board I have for the outboard relays.? ?I may have some other "power meters"? [these allare just simple rf voltmeters posing as wattmeters]? and see if I get any more believable answers.??

Thanks,

gordon gibby kx4z

I've always said I love standards.

They're just so FLEXIBLE!

73,
Gwen NG3P

When changing frequency or trying to step through the menus my encoder has a very annoying behavior. Sometimes with a single click it will act like 2 or 3 clicks. Sometimes you have to rotate it 2 or 3 clicks to make any change at all. So for example: lets say you are on 7.039.900 and you want to go to 7.040.000. You might have to do something like this: Right one click and you are on 7.040.200, left one click - no change, left one click and you are on 7.039.900, right one click and you are on 7.040.100..... and so on until you eventually land on 7.040.000.

I built two Raduino clones and they both operate this way. One is breadboarded with a parallel display and the other is built on a VK4PLN board with an I2C display. Both are running KD8CEC code V1.08.

The encoder I'm using is a brand new Bourns PEC16-4220F-S0024 part that I bought from Digikey. I have tried it with 0.01uf caps, 0.22uf caps and with no caps on the EncA and EncB lines and basically saw no change in behavior. ?I have used that encoder part in some other projects without issue. I tried one of the cheap e-bay encoders and it was even more annoying. Any ideas would be appreciated.

Spot on Iz.

WA8TOD

On Sat, 25 Aug 2018 14:33:10 -0700
"Eddie Esserman" <ee@...> wrote:

Hi, maybe these 2 links are what you are looking for?
I know its a real chore to dig thru all the various links
out there, lucky I had these bookmarked.

I avoided the problem with a paddle by using an
external electronic keyer, which feeds the straight key setup.

# the wiring


# the fine tuning thru the menu using the KD8CEC sketch


Joe
KN4OND

Could someone walk me through the menu to turn on the keyer?? I get dots, but no dahs, just out of the installation of the correct resistors.? And get straight key working fine.
Some where in the setup menu I do recall seeing a keyer page, but I'll be darned if I can find it. Checked all resistances and they are spot on for both dots and dahs.? And I'm at duh.
Thanks. 73.? All this assumes I still remember the code.

Eddie

Obligatory .

All :

This is a what I? sent on to AJP..?
I got a replacement Raduino board for? $35 US sent via DHL from HF Signals, which I plan on keeping as a spare.
I managed to replace the Nano on my original Raduino board , not too difficult and definitely cheaper but something I hope not to repeat !
The new Raduino boards come with a plug in Nano so much easier replace.
Regards,?
Malcolm

as per explanation of how others had purchased replacements from HF Systems

I added the comment that having a second source was also a nice thing so patronising the second supplier , the Triumvirate was not a? bad idea for replacements.

Why I should be addressed in capital letters is beyond me...? so it goes.. chill out. -TEF

I trust you Allison. Up to now I followed two rules of thumbs: 1) check the SWR with a proper load. 2) if and only if SWR was found close to 1 at a frequency, check the SWR without any load. If and only if in this case SWR is very high, at least greater than 10, losses are acceptable. If SWR is around 5 half power is lost into heat. If SWR is close to 1 everything goes into heat.

Timothy,

DO NOT PRIVATE EMAIL ME.? You are plonked, Clear!

开云体育

As a youngster I wondered why the tips on my Weller soldering gun broke after intense use.? I wired large relay terminals, switches, and small light bulbs for projects.? Turns out the solder dissolves copper, so little by little the tip would get eaten away.? Copper or alloys might also dissolve in lead-free solders, which leads to soldering-iron degradation.?

Some time ago a company in the UK sold solder with a small amount of copper in it, which stopped or reduced the decay of iron tips.

I think choice of solder manufacture is a personal just like the style of iron.
What works for one doesn't for another, I just don't get along with (genuine) HAKO.

It's possibly the Multicore Solder,? SAVBIT product you are referring to. Now owned by Loctite / Henkel.
It's being in the product catalogue since the early 1980's, a long before leadfree...
We had commercial contracts that specified by name it was to be used, personally I didn't note much difference compared to the normal brew.

Leaded Solder is still freely used in UK / EU.? Automotive, Military, Telco, Aviation, Medical electronics are all exempt from the green laws, basically anything that needs to work is exempt,
and is the choice of a particular manufacture.


It's only consumer electronics, that's legislated as being lead free.
To compound the problem the common practice is the dross gets skimmed off the solder bath,
Returned to the supplier for refining & reuse in the next batch of solder pellets for cheapness.....
If it's not a dry joint, swap the panel. Still doesn't work? then it's for recycling....

It always a laugh when at Hamfests to see people selling the "last few rolls of leaded solder, for double or triple the price of what it costs from a trade supplier.
Where do they keep finding this new "old stock" that was banned in 2006?? ;-)

Alan
?

For an interesting article about copper dissolving in lead-free solders, see:
--
Jon Titus, KZ1G
Herriman, UT USA

Great news.

Allison

Timothy,

You should check the site first.? No such reference.? They may sell them
but there was no reference on the page I could find.

of course one can email them and ask...

Allison

Could someone walk me through the menu to turn on the keyer?? I get dots, but no dahs, just out of the installation of the correct resistors.? And get straight key working fine.
Some where in the setup menu I do recall seeing a keyer page, but I'll be darned if I can find it. Checked all resistances and they are spot on for both dots and dahs.? And I'm at duh.
Thanks. 73.? All this assumes I still remember the code.

Eddie

Iz oos,

Depending on a few things self resonance is a bad thing.? For that transformer its
likely the core would absorb a lot of power as a side effect of the circulating currents
in the wire.? After all it showed a good SWR so the power is going somewhere.

As to SWR and wide band transformers.? I disagree, however I do that knowing full
well SWR (S11) is only a partial measurement.? ?It speaks to the source being
reflections or?not but not one clue if the power (all of it) makes it to the desired
load. A through measurement (S21) will provide a better idea of if the SWR is
good because its? delivered or absorbed and to what extent.? You must do both
or the image is incomplete.??

So at best the SWR is a suggestion of some level of merit but also incomplete.

Allison

Yes Warren also a long run of unterminated RG174 shows an acceptable SWR.

Allison... it must be a Millennial thing !!.? (the lack of memory /IT)

Seriously-? there have been other posts that HF signals will sell new Raduinos at USD 35 plus courier charges (however my guess is they do them as only a small extra production run so you takes yer chances on how many they have to sell at any given time ).? Look at HF Signals pages for any email addresses ....