On Sat, Dec 16, 2017 at 09:34 pm, Vince Vielhaber wrote:

The idle current you adjust is measured from the PA voltage and the
on-off switch doesn't switch that (unless you hooked it up to the
switch
as well).

The PA voltage is going through the switch as well. I measured from the
DC plug to the base of the positive that feeds the PA. It does double
when I click PTT, but that's it. I'm set on 200ma so I'm assuming I'm
getting like 5.6 - 5.8 milliamps through it when I press PTT and 2.6-2.8
just idle.

Also at 2 feet from the receiving rig, the dummy load is sufficient. No
need for an antenna.

With the antenna, do you receive anything on the BitX?

Vince.

No. I didn't hear anything, but the antenna was on the floor. I tuned my
HF rig to a really strong signal and tried to find it using the Bitx40
but it never picked anything up.

I'm very distressed right now. My 9 year old asked for one for Chanukah
built inside a lunchbox. She studied and got her general just so she
could have it. She's worked really hard and I've already given her an
antenna and coax. Then, today I finished the build, and tried to test
it.... and it failed.

Ok. I had built it with a buck converter (I think is what they're
called) to turn 12v into 24 volts. So, the first thing I did was to turn
RV1 all the way down. I hooked up a cable and a dummy load into the
cable. I set my meter on 200ma. I measured from the DC plug to the
on/off switch. I got 2.8 I think it was...it doubled when I clicked PTT.
I tried measuring voltage from the dummy load and got nothing. I took
the buck converter out of the circuit where it was powering the final.
With 12 volts powering the final, no change. I tried adjusting both RV1
and RV136. No change. I tried tuning it to a frequency, tuning my HF rig
to the same frequency, hooking up an actual antenna (laying on the
wooden floor though) and transmitting. Didn't hear anything in the HF
rig two feet away.

I had a computer mic hooked up as the mic. Tried saying hello in it
loudly...nothing. I wired up the electret mic that came with the kit.
Nothing in it either. When I push the PTT, I hear a click from the radio
and it does double (milli amps?), but that's it.

Works even with five. I left the usb cable connected From the pc and switched off the dc suppy. Kill me, but it continued to receive at low volume.
- f

Have you looked at threaded inserts?? Think of a pipe nipple that is threaded internally and externally.

There are several brands.? This is the first one I found.? If you have a real hardware store with aisles full of bins and trays of weird fasteners you might find some you can actually put your hands on and find nuts and washers and bolts that work.

Simon:

I think your comment is a bit harsh and 1) I did not see it as a religious or political comment, but rather in line with my comments, and 2) this is a Forum and not air waves regulated by the FCC. Expressing one's opinion "off the air" is a Constitutional right in the US protected by the First Amendment.

Jack, W8TEE

---

From: Simon Thompson <simonthompson67@...>
To: [email protected]
Sent: Saturday, December 16, 2017 7:41 PM
Subject: Re: [BITX20] ?BITX as a Tool for Recruiting New Hams

Please keep your political/religious commentary off this forum. It is not, as you should know, being a licensed amateur, appropriate to discussions of amateur radio. You should know it, because it is a condition of your license.

Simon

VE7SXS

On Fri, Dec 15, 2017 at 9:13 AM Werner Vavken <werner.vavken@...> wrote:

Thanks, Jack. I have been working at private, accredited ?Christian schools for the pat 14 years and they allow people from colleges & ?industry to teach as long as they show "some progress towards getting certified" as a high school teacher with the ACSI. That’s quite easy, really.

I don’t have a teaching credential either, just a BSEE, extensive MSEE course work and a MaEd.

Sadly the public school system is paralyzed with this thinking that a teacher MUST have a teaching credential to teach. There should be other ways to become a public school qualified teacher.?

Warmly,

WERNER G VAVKEN ? BSEE, MaEd

STEM Director

Rancho Christian School

-303-1408 ?x6157

Cell: ? ?408-375-6165

On Dec 15, 2017, at 8:53 AM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:

Werner:

That is so cool! I checked with a local high school when I was in Indiana about teaching a ham radio class as part of the STEM system. Even though I have a Ph.D. and 40 years of university teaching, I was told by the Principal I was not "properly qualified" to teach a HS class in IN. Maybe I should try again, as I now live in OH.

Dennis is a wonderful person to work with. I know just enough EE stuff to make him tear his hair out when I ask a question. Still, he has the patience of Job and can always frame an answer I can understand...and that's a?real?talent!

Thanks for this email...maybe I can fool some OH administrators into letting me in the classroom.

73,

Jack, W8TEE

---

From:?WERNER G VAVKEN <wernervavken@...>
To:?[email protected]?
Sent:?Friday, December 15, 2017 11:42 AM
Subject:?Re: [BITX20] ?BITX as a Tool for Recruiting New Hams

Jack, you are spot on. It is mission critical to get new hams ACTIVE both on the air (including HF) and also to get them on the road to get their hands dirty building hardware, including antennas.? The uBitx is a great way to do this that I will use next month…see below. I ordered 8 of them and 8 plastic cases from BangGood.?

I am a retired EE with over 30+ years experience in designing hardware and radio systems from audio thru 40GHz. Teaching is my new passion. I have been teaching ham courses (and how to put science experiments on the ISS) at the high school level for over seven years. My ham classes (disguised with the name Satellite Tracking) is a high school level ?“science elective” and I offer it over three semesters to allow students to earn their Tech, General and Extra class licenses. Doing it over a 4+ month period, for each level, I actually get to TEACH the relevant material, have students build stuff and get them on the air. They also learn a lot about tracking satellites.

Every one of my new ham student “earns" an Alinco DJ-G7 triband HT ?and an Elk LPA Antenna to track satellites if they pass the Tech exam. They also build an EggBeater antenna I designed and presented at recent Pacificon events,?

Next Semester they will each build one of the uBitx transceivers and a 40M dipole and they WILL get on HF!

BTW, Jack, we have a mutually close friend, Dennis -W6DQ, I manage the Collins Collectors Association West Coast Friday night NET on 3895 at 7PM. He is one of my NET control operators for that net!

Thanks for all you do for our Ham Radio hobby and, of course, your contributions to this uBitx, etc.

?

73’蝉

<PastedGraphic-1.tiff>

WERNER G VAVKEN, WB6RAW

wernervavken@...

Cell: 408-375-6165

On Dec 15, 2017, at 8:24 AM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:

I changed the topic to narrow the focus. You're right, Joe, the social media sites have a lock on young people. My club gives the FCC exams every month (except Dec.) for free and we always have people show up; sometimes as many as three dozen. Most are going for the Tech license to get their toe wet. Then they buy a 2M HT and we never see them again. I did run into one guy almost a year later and asked how he was enjoying his license. He said: "I haven't done anything for the past several months. It doesn't even let me do what my cell phone does." We need to get Tech's more than just a small slice of 10M in the HF spectrum. Otherwise, I think they are missing out on 90% of what ham radio has to offer. When I was a Novice, we had small chunks of HF (e.g., 40M) to play with. True, you were rock-bound and limited to 75W and CW, but I spent almost all of my time on 40M. Britain has had more success than we have with young people, and I think part of the reason is because they give their Tech-equivalent hams small slices of spectrum on all bands, including HF. They are limited to 5W, but at least they can chase DX. Other than the rare atmospheric events, DX on 2M is a couple of counties away with the HT that most end up buying.

I look around at my club and I can almost hear the arteries calcifying. I can say that 'cuz I'm two years younger than dirt so I know the aging membership issues quite well. We need some younger members; perhaps younger than those who are recently married and starting their families. The real solution: I don't know, but there are things we can do. I have a FB account, but probably use it twice a year. I'm not on Twitter. I need to root around there for a while and see what I can do for the cause.

Jack, W8TEE

<PastedGraphic-1.tiff>

This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager.?This message may contain?confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.

Ignore that. Wearing the wrong glasses and thought you were looking for
attenuators, not terminators.

Vince.

Greetings RF Gurus - a noob has ascended to bother the masters. ;)

Would someone please point me to a schematic or other resource that would help me determine the correct resistor values so that I may construct a pair of resistive terminators?? I'm trying to figure out how to measure the impedance of the two crystal filters I've constructed.? VK2SJA has an excellent blog post, but I'm missing a vital piece of tribal knowledge, apparently.? (Ok, I'm missing a number of pieces of tribal and non tribal knowledge.? hi hi)? He used a pair of terminators with pots to determine his termination needs.


I built a pair of 8 crystal filters for a ?BITX, and assuming the 4:1 match, wound a pair of center-tapped toroidal transformers.? My new Sweeperino (a magical device that makes the invisible visible) showed me that my impedance matching guess was incorrect....like 10 dB of ripple's worth of incorrect.? :D

Iterating DISHAL suggests the filters are 75 Ω.? I'd like to measure them to know for sure.

Thanks all
Andy, KG5RKP

andy,?

this a terribly confusing topic. let me attempt it as best as i can from the phone.

a filter can be driven and terminated with any impedance without the rf police turning up at your doorstep.

the question, really, is what do you expect the filter to do. at every termination, it will show a different ripple and passband. here is a quick summary :

higher the value if caps, smaller the bandwidth. lower the impedance, lower the ripple. low ripple also means, worse skirt.

search out w7zoi paper on ladder filters.

- f

?

On 17 Dec 2017 8:51 am, "AndyH" <ahecker@...> wrote:

Greetings RF Gurus - a noob has ascended to bother the masters. ;)

Would someone please point me to a schematic or other resource that would help me determine the correct resistor values so that I may construct a pair of resistive terminators?? I'm trying to figure out how to measure the impedance of the two crystal filters I've constructed.? VK2SJA has an excellent blog post, but I'm missing a vital piece of tribal knowledge, apparently.? (Ok, I'm missing a number of pieces of tribal and non tribal knowledge.? hi hi)? He used a pair of terminators with pots to determine his termination needs.


I built a pair of 8 crystal filters for a ?BITX, and assuming the 4:1 match, wound a pair of center-tapped toroidal transformers.? My new Sweeperino (a magical device that makes the invisible visible) showed me that my impedance matching guess was incorrect....like 10 dB of ripple's worth of incorrect.? :D

Iterating DISHAL suggests the filters are 75 Ω.? I'd like to measure them to know for sure.

Thanks all
Andy, KG5RKP

?

?

?

I don't have a URL handy, but if you google "pi attenuator" you should
find the tables of what resistor combinations to use for various levels
of attenuation. There should also be a calculator or two in the mix.

Vince.


On 12/16/2017 10:20 PM, AndyH wrote:

Greetings RF Gurus - a noob has ascended to bother the masters. ;)

Would someone please point me to a schematic or other resource that
would help me determine the correct resistor values so that I may
construct a pair of resistive terminators? I'm trying to figure out how
to measure the impedance of the two crystal filters I've constructed.
VK2SJA has an excellent blog post, but I'm missing a vital piece of
tribal knowledge, apparently. (Ok, I'm missing a number of pieces of
tribal and non tribal knowledge. hi hi) He used a pair of terminators
with pots to determine his termination needs.


I built a pair of 8 crystal filters for a ?BITX, and assuming the 4:1
match, wound a pair of center-tapped toroidal transformers. My new
Sweeperino (a magical device that makes the invisible visible) showed me
that my impedance matching guess was incorrect....like 10 dB of ripple's
worth of incorrect. :D

Iterating DISHAL suggests the filters are 75 Ω. I'd like to measure
them to know for sure.

Thanks all
Andy, KG5RKP

Greetings RF Gurus - a noob has ascended to bother the masters. ;)

Would someone please point me to a schematic or other resource that
would help me determine the correct resistor values so that I may
construct a pair of resistive terminators? I'm trying to figure out how
to measure the impedance of the two crystal filters I've constructed.
VK2SJA has an excellent blog post, but I'm missing a vital piece of
tribal knowledge, apparently. (Ok, I'm missing a number of pieces of
tribal and non tribal knowledge. hi hi) He used a pair of terminators
with pots to determine his termination needs.


I built a pair of 8 crystal filters for a ?BITX, and assuming the 4:1
match, wound a pair of center-tapped toroidal transformers. My new
Sweeperino (a magical device that makes the invisible visible) showed me
that my impedance matching guess was incorrect....like 10 dB of ripple's
worth of incorrect. :D

Iterating DISHAL suggests the filters are 75 Ω. I'd like to measure
them to know for sure.

Thanks all
Andy, KG5RKP