/g/qrp-tech

Re: [azqrp] AZ ScQRPions Meeting and the Superstition Hamfest

scotty@... (Scotty WA2DFI) — Sat, 07 Dec 2024 01:04:19 -0800

A bunch of us are going to the Longhorn Steak House on Alma School between Southern and US60. Address is 1434 S Alma School Rd, Mesa
They have lunch specials on Saturday including a $9 chicken sandwich and a $10 cheeseburger, both very excellent. Normally kind of expensive, but for lunch (including Saturdays!), a good deal these days. (They also have some salads on lunch special if you are into those.)
It opens at 11AM and is 1 mile from the hamfest. See you there!!!
Wish you could join us, Mike! :-(
73,
Scotty WA2DFI

Fixing the PTO on a Direct Conversion Receiver

n2cqr@... (Bill Meara) — Wed, 15 Mar 2023 09:48:38 -0700

I thought the qrp-tech group be interested in this very simple fix to a very simple direct conversion receiver PTO:
https://soldersmoke.blogspot.com/2023/03/fixing-tuning-problem-in-high-school.html

Background on the project here (keep scrolling down -- there are about 28 posts!):
https://soldersmoke.blogspot.com/search/label/TJ%20DC%20RX

73 Bill N2CQR

File Notifications

@... — Mon, 13 Mar 2023 16:17:59 -0700

The following files and folders have been updated in the Files area of the [email protected] group.

* /K8IQY Home Brew 15-Meter Direct Conversion Transceiver/DC-HB Rx Front-EndV1-Schematic.pdf ( /g/qrp-tech/files/K8IQY%20Home%20Brew%2015-Meter%20Direct%20Conversion%20Transceiver/DC-HB%20Rx%20Front-EndV1-Schematic.pdf )

*By:* Jim Kortge <jim.k8iqy@...>

*Description:*
This is the schematic for the Front-end filter and RF pre-amp for the 15-Meter home brew transceiver using a direct conversion receiver. It consists of a classic, double tuned set of resonators followed by a J310 JFET RF Amplifier. It is designed to drive the 1500 Ohm input impedance of the SA612 mixer in the front-end of the direct conversion receiver. It has a gain of about 15 dB. Jim, K8IQY March 13, 2023

---

The following files and folders have been uploaded to the Files area of the [email protected] group.

* /HB-RxFrontend-LogSweep.bmp ( /g/qrp-tech/files/HB-RxFrontend-LogSweep.bmp )

*By:* Jim Kortge <jim.k8iqy@...>

*Description:*
This is a Spectrum Analyzer plot of the 15-Meter Transceiver front-end filter- RF amplifier. Jim, K8IQY March 13, 2023

File /K8IQY Home Brew 15-Meter Direct Conversion Transceiver/DC-RxMixer-AudioV2-Schematic.pdf uploaded

@... — Mon, 13 Mar 2023 16:04:26 -0700

The following files and folders have been uploaded to the Files area of the [email protected] group.

* /K8IQY Home Brew 15-Meter Direct Conversion Transceiver/DC-RxMixer-AudioV2-Schematic.pdf ( /g/qrp-tech/files/K8IQY%20Home%20Brew%2015-Meter%20Direct%20Conversion%20Transceiver/DC-RxMixer-AudioV2-Schematic.pdf )

*By:* Jim Kortge <jim.k8iqy@...>

*Description:*
Receiver schematic for the home brew 15-Meter transceiver that I am building. It is complete, except for the Audio AGC section. The first version that I tried didn't work at all well, so back to the drawing board. I'll figure something out eventually. In the mean time, this much works just fine. Without the front-end filter section, I can copy signals on any of the ham bands, just by setting the VFO to the correct frequency. I've tried 80, 40 and 20 meters, and a quick foray to 15 MHz for WWVB. I'll update and release the PCB that I built it on when the Audio AGC issue is resolved. Jim, K8IQY, March13, 2023

Re: [qrptech] [qrp-tech] Added Folder /K8IQY Home Brew 15-Meter Direct Conversion Transceiver

jim.k8iqy@... (Jim Kortge, K8IQY) — Sun, 12 Mar 2023 10:05:40 -0700

Hi Alan,

Here:

</g/qrp-tech/files/K8IQY%20Home%20Brew%2015-Meter%20Direct%20Conversion%20Transceiver> ( /g/qrp-tech/files/K8IQY%20Home%20Brew%2015-Meter%20Direct%20Conversion%20Transceiver )

Nothing in that folder at the moment, but I'll try to get some stuff there before the end of the day. I've got the receiver board almost done, so I'll get it and the front-end filter (already built) stuff there soon hopefully.

72/73 and thanks for your interest,

Jim, K8IQY

Added Folder /K8IQY Home Brew 15-Meter Direct Conversion Transceiver

@... — Sun, 12 Mar 2023 07:12:27 -0700

Jim Kortge <jim.k8iqy@...> added folder */K8IQY Home Brew 15-Meter Direct Conversion Transceiver*

Availability of a New MagicBox Design

jim.k8iqy@... (Jim Kortge, K8IQY) — Fri, 25 Mar 2022 13:27:44 -0700

Good morning everyone,

Today, we are announcing the release of a new MagicBox V2.5 design.

The K8IQY/KU4QO MagicBox V2.5, is an updated version of the project designed by K8IQY in 2013 and kitted by the 4 State QRP group. In the prior version, the MagicBox could be used to connect a receiver and a transmitter together to operate as a transceiver, with all of the RF switching and Audio Muting handled by the MagicBox. It used a programmed microprocessor to control the functions within the box. The updated version provides all of the RF Switching and Audio Muting functionality of the original, along with the addition of an internal, speed adjustable, CW Keyer, power control for transmitters requiring an external power source to be switched, such as a Tuna Tin 2, and a redesign of the PIN diode RF Switching circuitry to handle higher transmitter power levels. This version can handle transmitters up to 20 watts, with very low loss. In addition, the CW keyer part of the system can be used as a standalone code practice oscillator or keyer for a rig not having that feature. This version uses an Arduino Nano clone for control, so that operational changes can be made by the builder.

All of the project documentation lives on GitHub,

<https://github.com/ku4qo/MagicBox2.5> ( https://github.com/ku4qo/MagicBox2.5 )

and is in the public domain, including the Gerber files for PCB manufacturing, Bills of Material, 3D printing file (STL) for the case, along with other useful documentation. Builders are encouraged to team up to acquire PCBs and parts for this project, and support each other.

72 and have fun,

Jim Kortge, K8IQY and Mike Maiorana, KU4QO designers
03/25/2022

Excess Parts, CA3039 Gone

@... — Thu, 28 Jan 2021 10:55:53 -0800

All,

Anyone who missed the first round of parts also missed the CA3039s;
they're all gone. There's still plenty of PNP Transistors left though. Same
request as before:

1. Email me your mailing address.
2. When the envelope arrives, try the parts. They're old and haven't been
stored for ESD, so try them out.
3. If you like them, put 2 single dollar bills in an envelope, fold them into
a piece of paper to make them more opaque, and send them to me to cover costs.
4. If you don't like them, don't send anything. You're not out anything.

--
--
Bill Lazure
W2EB

On 1/25/2021 at 3:46 PM, "Bill" <bill@...> wrote:

All,

I don't do paypal and don't want to, so let's try it this way:

1. Email me your mailing address and which parts you want.
2. When the envelope arrives, try the parts. They're old and haven't been
stored for ESD, so try them out.
3. If you like them, put 2 single dollar bills in an envelope, fold them into
a piece of paper to make them more opaque, and send them to me to cover

costs.

4. If you don't like them, you're not out anything.

By the way, I estimated poorly; there's only a couple hundred of the
CA3039.

Finally, the cost and hassle of sending these overseas makes this deal
prohibitive for me. US destinations only.

P.S. To whoever sent me a paypal without asking first, I don't want to
sign up for Paypal. Take your money back and send me your mailing address

and

we'll give the USPS some business.

--
--
Bill L
W2EB

On 1/23/2021 at 2:11 PM, "Bill" <bill@...> wrote:
All,

My employer tossed some old parts. I grabbed a box that contains
several thousand each of CA3039 (6 matched diodes, low capacitance, low
forward voltage) that might be useful for mixers, and MPS6518 (PNP General
Purpose in TO-92 package, compared to 2N3906).

If you need some send me buck and I'll put some in a padded envelope

for

you.

My address is good in QRZ.

Bill
W2EB

Excess Parts, next attempt

@... — Mon, 25 Jan 2021 13:47:02 -0800

All,

I don't do paypal and don't want to, so let's try it this way:

1. Email me your mailing address and which parts you want.
2. When the envelope arrives, try the parts. They're old and haven't been
stored for ESD, so try them out.
3. If you like them, put 2 single dollar bills in an envelope, fold them into
a piece of paper to make them more opaque, and send them to me to cover costs.
4. If you don't like them, you're not out anything.

By the way, I estimated poorly; there's only a couple hundred of the
CA3039.

Finally, the cost and hassle of sending these overseas makes this deal
prohibitive for me. US destinations only.

P.S. To whoever sent me a paypal without asking first, I don't want to
sign up for Paypal. Take your money back and send me your mailing address and
we'll give the USPS some business.

--
--
Bill L
W2EB

On 1/23/2021 at 2:11 PM, "Bill" <bill@...> wrote:

All,

My employer tossed some old parts. I grabbed a box that contains

several thousand each of CA3039 (6 matched diodes, low capacitance, low
forward voltage) that might be useful for mixers, and MPS6518 (PNP General
Purpose in TO-92 package, compared to 2N3906).

If you need some send me buck and I'll put some in a padded envelope for

you.

My address is good in QRZ.

Bill
W2EB

Excess Parts

@... — Sat, 23 Jan 2021 13:25:11 -0800

All,

My employer tossed some old parts. I grabbed a box that contains several thousand each of CA3039 (6 matched diodes, low capacitance, low forward voltage) that might be useful for mixers, and MPS6518 (PNP General Purpose in TO-92 package, compared to 2N3906).

If you need some send me buck and I'll put some in a padded envelope for you.

My address is good in QRZ.

Bill
W2EB

Happy New Year 2021

w4bws1@... (Donald Sanders) — Thu, 31 Dec 2020 09:13:03 -0800

2020- wow, what a year. My Happy New Years wish is for 2021 to be much better for everyone.
My special thanks to all who ordered my e-book. Prior to covid-19 I procured my breathing medicine for $10 to $20 a month.
With all the travel and shipping limitations due to covid I am forced to procure the meds in the USA at $98 a month.
Your orders have assisted that without cutting my food budget. Hopefully that will continue in 2021.
See more at QRZ.com /db/W4BWS
So Happy New Year 2021 and for to all have a more healthy, secure and prosperous 2021.
I will be looking for everyone on slow key night December 31 and during January 1.
72/73
Dr. Don W4BWS
SKCC # 81C
God Bless All
"Basic Wire Antennas" my new book available
for $5 sent to my email address via paypal friends.
More info at W4BWS on QRZ.com.

PCBs for NorCal 2N2/XX Rig

jim.k8iqy@... (Jim Kortge, K8IQY) — Sun, 10 Nov 2019 16:21:03 -0800

All,

After a lot of discussion with close associates and thinking through all of the issues with making the PCB available for the NorCal 2N2/XX rig, I've decided not to do it. Here are the main reasons why.

That PCB is really dense, so much so that many of the support issues I had to deal with came down to builders putting the parts in the wrong place. In addition, there are 300 parts needed for that PCB, many of which are no longer available, and some of them were quite expensive like the 10-turn tuning pot at nominally $10.00 per unit.

It is obvious to me that a substantial amount of time would be required to find suitable replacements for the extinct parts; I have neither the time nor the inclination to do that for a design that is now 11 years old. Additionally and realistically, since I was the designer of the rig, most of the support questions would come to me; I've moved on and can't get back into that mode. When the kit launched, support issues took over my life for most of a year. I'm going to be selfish and not let that happen again.

Finally, all of the documentation for the 2N2/XX is on my web site: www.k8iqy.com ( http://www.k8iqy.com ) so you can get the docs, build any of the 3 bands Manhattan-style, like I did originally, or make your own PCB using DipTrace or KiCAD with the changes you see fit (like DDS tuning and Digital Display) on a PCB sized to your liking.

So, I hate to disappoint all of those clamoring for 2N2/XX PCBs, but for the reasons above, (and a lot of other unspoken reasons) it won't be happening.

72/73 to all and enjoy the upcoming holidays,

Jim, K8IQY

PS....thanks to all who offered to help out with making boards available, I truly appreciate your support.

New Group Created: qrptech@groups.io

geocrasher@... (Ryan Flowers) — Mon, 04 Nov 2019 14:18:03 -0800

Hello everyone,

I have created a new group at [email protected]. Please do join. You all might not know me because I use joined, but owning groups of various types is something I've done a lot of. Thank you for allowing this message through moderation, Chuck.

73! (or 72, if you prefer)

--
Ryan Flowers W7RLF
https://miscdotgeek.com

EOL

chuck.adams.phd@... (chuck adams) — Mon, 04 Nov 2019 08:29:27 -0800

OK, proved my point that there is nothing left for this group
to accomplish technically.

Going to moderated mode and postings will be left to die after
14 days in the queue.

End of this group. Take discussions to qrp-l and may the
electromagnetic force be with you always.

Everything up to this point will be left as is until
groups.io decides to start charging fees.... Please
do not migrate files to other groups. They were put
here by the owners and they have all rights to same.

ciao,

chuck, k7qo

Re: QRPGuys DSB Digital Transceiver

@... — Mon, 04 Nov 2019 08:15:37 -0800

Comparing LA to SF is like comparing an FTDX101 to a QCX. Los Angeles has a population of 4 million spread over a radius of 30 miles. San Francisco is <800,000 people on a small peninsula. Roughly the same as Jacksonville, Austin, Seattle and Indianapolis. It greatly matters what part of any of those cities you use as a comparison. Tourists and business travelers rarely see more than a small subset of any city they visit even over several years. That's not enough time to declare on of the world's largest and most interesting cities as worse than any other city.

Eric

Re: QRPGuys DSB Digital Transceiver

jjpurdum@... (Jack) — Mon, 04 Nov 2019 07:32:45 -0800

I agree. I haven't been to LA for several years, but it was worse than what I saw in SF. For years I went to the SF Software Development Conference and stayed with a friend in Golden Gate Park. What I really liked about it was everything you needed--restaurants, grocery stores, dry cleaning, bakery, etc.--was within walking distance. It was a true neighborhood with dozens of Ma-and-Pa stores. He moved to Davis, CA, so I don't know if it's the same. I sure hope so.
Jack, W8TEE

Re: QRPGuys DSB Digital Transceiver

@... — Mon, 04 Nov 2019 07:10:04 -0800

Jack,

I am a San Francisco kid. I went to school in San Mateo (25 miles south).
But before WWII I did live in SF on the west side.

I spent most of my career as an EE in Silicon Valley. I left there in 1995
and moved to Sacramento. Then in 2000 I moved to the Seattle area.

I do look back at SF from time to time but it will never be like it was in
my youth.

But I think LA is actually worse.

Bob Macklin
K5MYJ
Seattle, Wa.
"Real Radios Glow In The Dark"

Re: QRPGuys DSB Digital Transceiver

jjpurdum@... (Jack) — Mon, 04 Nov 2019 06:12:41 -0800

Interesting question about the geographic distribution of activity. I wonder if it's because the West has a lot of "young" people, whereas the East and Midwest is a little older? I was in CA a month ago and was really saddened by what I saw in SF versus 20 years ago. The wharf area was still nice, but get off the tourist areas and it just seemed "dirtier and dingy" to me. I also saw human waste on the sidewalks, used needles in the gutters, and people sleeping in doorways...not at all like what I remember from the past.

Oh well, I'd never make it in CA anyway: I'm old, fat, conservative, and don't like avocados.
Jack, W8TEE

Re: QRPGuys DSB Digital Transceiver

zfreak@... (Michael Maiorana) — Mon, 04 Nov 2019 04:24:13 -0800

Thanks Chuck.
It seems to me that the conversations here can easily slide back into the
qrp-l group. Lots of good information in both places.

Good luck with your papers Chuck!
Mike M.
KU4QO

On Sun, Nov 3, 2019 at 7:16 PM chuck adams <chuck.adams.k7qo@...>
wrote:

This group is coming to its end of life. At the end of the year I will
disable all posting, but the material files and messages will remain
intact for the duration of the life of groups.io as long as we are not
charged for the use of the space. Greed seems to be kicking in on
the Internet and every one wants to make money.

ciao,

chuck, k7qo

Re: QRPGuys DSB Digital Transceiver

ab7vf@... (jim) — Sun, 03 Nov 2019 21:41:25 -0800

Yes ...I read the article ...Just thought it was interesting that it was referenced as a "phasing" with no (or minimal) mention of synchrodyne ...that was hot stuff at one time ....
Jim