Date   

Re: Chinese Pixie Part II

John Clements
 

I agree Lee, we did this at our local club to generate activity and get some of the newer tech's, with rocks on their segment and the supplied 50 ohm resistor, experience in building and to show the fun they can have getting their licenses upgraded.  In short, most of these little kits won't make it on the air but we all had a blast building and making a few table-top QSO's for mere pennies.  There was enough fun that a few of the new tech's have either already upgraded or want to start a general class this fall.  Even better is getting constantly asked "what's the next project?"  Mission accomplished! 


Re: Chinese Pixie Part II

Bill Cromwell
 

Hi,

I just got one of those kits as a door prize at the Michigan QRP Club annual picnic. I'll build it up but I'll use replacement transistors as suggested and probably get a different crystal even though I have an Extra Class ticket - just to make sure I have more hams to talk to. Thanks for the tips about the transistors and the output filters.

On 07/13/2015 12:40 AM, Lee l@w0vt.us [4sqrp] wrote:

The condenses of those that have built these rigs is, they do work "as is" with less then advertised power because the two transistors are of poor quality. Put in two decent transistors and they put out much more power. As for the two included cores, any ham with a little knowledge realizes the powdered iron core goes in the pi-network. I assume the kit provider figured US hams were at least smart enough to realize this. I have numerous examples of these rigs myself, but have not bothered to date to build them up. When I do it, I'll make sure to use a couple adequate replacement transistors. These little kits are a super bargain, they just need a little "tweeking". They would make excellent little rigs to be used by a local club for local code practice amoung themselves. Crystals to change them over to higher 40 meter frequencies a Tech can be purchased for around $2.00. The silk screened glass PC board alone is worth $7!!!
Lee, w0vt


Send in your score

John Lonigro
 

Today is Monday. If you participated in the SSS last night, please get your score in ASAP. I have a medical test later this week and need to be finished tallying the scores by Wednesday morning. Otherwise, I don't know when I'll get to it. With three birthdays plus a relative having knee surgery next week, my spare time is going away until August.

Bottom line: Please get your score in today if at all possible.

Thanks and 72,

John AA0VE


Re: Chinese Pixie Part II

Don Wilhelm <w3fpr@...>
 

I doubt that a single PI section low pass filter can achieve the -43 dB 2nd harmonic suppression that is required by the current FCC regulations.
Many old designs suffer from that same limitation.  There is no longer an exemption for QRP transmitters.
The original Pixie was OK because it was built before that regulation was in place.  But all transmitters built after January 1, 2003 must meet that requirement.  See FCC part 97.307(d).

73,
Don W3FPR

On 7/13/2015 12:40 AM, Lee l@... [4sqrp] wrote:
 

  As for the two included cores, any ham with a little knowledge realizes the powdered iron core goes in the pi-network.  I assume the kit provider figured US hams were at least smart enough to realize this.



Re: Chinese Pixie Part II

Leland L. Bahr
 

The condenses of those that have built these rigs is, they do work "as is" with less then advertised power because the two transistors are of poor quality.  Put in two decent transistors and they put out much more power.  As for the two included cores, any ham with a little knowledge realizes the powdered iron core goes in the pi-network.  I assume the kit provider figured US hams were at least smart enough to realize this.  I have numerous examples of these rigs myself, but have not bothered to date to build them up.  When I do it, I'll make sure to use a couple adequate replacement transistors.  These little kits are a super bargain, they just need a little "tweeking".  They would make excellent little rigs to be used by a local club for local code practice amoung themselves.  Crystals to change them over to higher 40 meter frequencies a Tech can be purchased for around $2.00.  The silk screened glass PC board alone is worth $7!!!
Lee, w0vt

Extra class is below 7025 kHz, so I don't believe the author of that webpage knows what he is talking about.
So much for stuff from China.  I would not pay even $7 to find out if it was worthwhile.

73,



Re: Chinese Pixie Part II

Leland L. Bahr
 

The condenses of those that have built these rigs is, they do work "as is" with less then advertised power because the two transistors are of poor quality.  Put in two decent transistors and they put out much more power.  As for the two included cores, any ham with a little knowledge realizes the powdered iron core goes in the pi-network.  I assume the kit provider figured US hams were at least smart enough to realize this.  I have numerous examples of these rigs myself, but have not bothered to date to build them up.  When I do it, I'll make sure to use a couple adequate replacement transistors.  These little kits are a super bargain, they just need a little "tweeking".  They would make excellent little rigs to be used by a local club for local code practice amoung themselves.  Crystals to change them over to higher 40 meter frequencies a Tech can be purchased for around $2.00.  The silk screened glass PC board alone is worth $7!!!
Lee, w0vt

Extra class is below 7025 kHz, so I don't believe the author of that webpage knows what he is talking about.
So much for stuff from China.  I would not pay even $7 to find out if it was worthwhile.

73,



Re: Chinese Pixie Part II

Dean LaClair
 

Rough bunch....Dang!  oughtta see me type after 3 or 4- 807's
Better yet, rip cw....lol
73 all
Dean

On Jul 12, 2015 11:24 PM, "John Clements jwc123@... [4sqrp]" <4sqrp@...> wrote:
 

Whoops, had a type-o on my web page.  The Chinese rigs are coming with 7.023 crystals.  I see some of the Epay places list them going from 7.023 to 7.026 but with HC49/s "rectangular AT Strip cut" crystals supplied you probably won't get a 3KHz bend.  Maybe 2KHz Max bend and lucky to get around 2.7KHz bend if you parallel two.  Changing to the larger HC49/u "circular AT cut" might get you to a 3.5KHz bend. Still a close shave for operating in the General class with an extra class rock.

Gee Wally..... I Guess I do know maybe just a little of what I'm talking about.  Just may not type it right .001% of the time.

72
John kc9on



On Sun, Jul 12, 2015 at 10:24 PM, Don Wilhelm <w3fpr@...> wrote:
You have got to be kidding - the webpage says the crystal is a 7027 and states that it in the *extra* class band.
Extra class is below 7025 kHz, so I don't believe the author of that webpage knows what he is talking about.
So much for stuff from China.  I would not pay even $7 to find out if it was worthwhile.

73,
Don W3FPR

On 7/12/2015 8:17 PM, jwc123@... [4sqrp] wrote:
 

Looks like you saw many of the same things I did during the build.  http://kc9on.com/ham-radio/chinese-qrp-kits/






Re: Chinese Pixie Part II

John Clements
 

Whoops, had a type-o on my web page.  The Chinese rigs are coming with 7.023 crystals.  I see some of the Epay places list them going from 7.023 to 7.026 but with HC49/s "rectangular AT Strip cut" crystals supplied you probably won't get a 3KHz bend.  Maybe 2KHz Max bend and lucky to get around 2.7KHz bend if you parallel two.  Changing to the larger HC49/u "circular AT cut" might get you to a 3.5KHz bend. Still a close shave for operating in the General class with an extra class rock.

Gee Wally..... I Guess I do know maybe just a little of what I'm talking about.  Just may not type it right .001% of the time.

72
John kc9on



On Sun, Jul 12, 2015 at 10:24 PM, Don Wilhelm <w3fpr@...> wrote:
You have got to be kidding - the webpage says the crystal is a 7027 and states that it in the *extra* class band.
Extra class is below 7025 kHz, so I don't believe the author of that webpage knows what he is talking about.
So much for stuff from China.  I would not pay even $7 to find out if it was worthwhile.

73,
Don W3FPR

On 7/12/2015 8:17 PM, jwc123@... [4sqrp] wrote:
 

Looks like you saw many of the same things I did during the build.  http://kc9on.com/ham-radio/chinese-qrp-kits/






Re: Chinese Pixie Part II

Don Wilhelm <w3fpr@...>
 

You have got to be kidding - the webpage says the crystal is a 7027 and states that it in the *extra* class band.
Extra class is below 7025 kHz, so I don't believe the author of that webpage knows what he is talking about.
So much for stuff from China.  I would not pay even $7 to find out if it was worthwhile.

73,
Don W3FPR

On 7/12/2015 8:17 PM, jwc123@... [4sqrp] wrote:
 

Looks like you saw many of the same things I did during the build.  http://kc9on.com/ham-radio/chinese-qrp-kits/





Re: Chinese Pixie Part II

John Clements
 

Looks like you saw many of the same things I did during the build.  http://kc9on.com/ham-radio/chinese-qrp-kits/


One thing I can't check was the output.  Would be interesting to see if a LPF is needed and what harmonics are coming out.


The A/C noise is terrible with a 35+ year old power supply but moving to a battery solved that problem.  Also no dice with FLDigi decoding in the daytime and ended up using an audio filter to remove the highs.  Can't complain after making a 280 miles QSO with it.  What more fun can you have for $7 now days?

I was disappointed in the Frog, definitely not the power out as claimed but with a simple cut and wire turned the RF gain pot into a RIT control.  Rockmite (non-PIC) version is nice but ended up jumpering out the CPU and fixed the audio "squeal" issue.  Want to try the newer Rockmite (w/ PIC) and see if it's any better.

The Chinese 49-er and tuner kits arrived in the mail yesterday.  Now just need to catch up at catching up and I can build/play with those also!

72
John kc9on


Re: What's it worth?

Rich Fowler <k8meg@...>
 

To get a feel for the value, go to EBay and search for J-37, J-47, J-38.

In my mind, if I used this key as a novice or one like it, which I did by the way, and I would like to have it for old time sake, I would probably spend $50 for it. But it would really be stretching my willingness to pay that much. When the price is between $25-30 that's closer than what I think they are worth. IMO. Some like to put a little polish on them and ask for the high dollar. They make a pretty key, but....

Unfortunately for me, but fortunate for the receiver, have given many of these keys to beginning hams with an inspiration of learning CW. That said, I have one of those military trainers with 10 J-37 keys that I would like to get rid of, but I don't want the keys removed and sold separately for $35-45 each. This is part of Military CW history. :)

Hope this helps.

72,
Rich K8MEG


What's it worth?

David Lininger
 

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

A friend just asked me what a J-37 key on a J-44 base is worth. Any idea
s?


- --
David Lininger, kb0zke
EM37kt
Rev. 2:10
kb0zke@gmail.com
-----BEGIN PGP SIGNATURE-----
Version: GnuPG/MacGPG2 v2
Comment: GPGTools - https://gpgtools.org

iQEcBAEBCgAGBQJVorP4AAoJECWcoyE8F88VLHIH+wU+EOPr1krnc09uDuqTB8b1
CSF+XaQIF5V4zGAgHsrQFCajGAQUTjzOYziYNtqSU4bYtnZlIt1s9HBsLEYWRlVa
E92JlDeXubTcJi5urgWAJGdkJf81B/7lZb2E99EgBCgg6mdIlBGwhPZy98A2tnyW
rOMbkqsOrleQHPabct2oIW/4/51q/zsr9Mmb5mSFbrMOYlQhAnquUoDW7IJm3LOh
+XQsdfSNfrnF9rbPvD9eX+kY9vNzGu7Djos2upnTvztEIKuORgKx+/Jl01C5ivVo
Z6Uufa14EoZw/Aj27i4AkaUJwRe6P2m5Tk0UpJbdJbk4PnFXxjVo6ghuabaMyz4=
=aiD8
-----END PGP SIGNATURE-----


SSS - last reminder

John Lonigro
 

Don't forget: Tonight is the July SSS. Get on the air from 7:00 pm until 9:00 pm (Ozarkcon time). Show everyone how much better your CW is after Field Day. The rules were in a previous email and won't be repeated.

If I'm not interrupted, I may try to get on the air myself tonight. We don't expect storms until tomorrow.

72,

John AA0VE


Re: Chinese Pixie Part II

ai9e_qrp@...
 

I fired up my Chinese Pixie last night.  The receiver is surprisingly sensitive, with MDS of about -115 dBm.  The sensitivity comes at a price, though.  The 5 kW AM station 20 miles up the road from us came through quite strong, as did a S9+ 60 Hz hum if I grounded the board.  Once night fell, and the AM station powered down, I could hear several CW stations though.

The pot on the board shifts bias on a 1N4001 diode in series with the crystal, and gives it about 2.5kHz tuning range

I tried hooking the audio output of the receiver to my laptop to see if it would work with FLDigi.  No dice.  The ground loop between the computer and antenna brought up the 60 Hz hum and overwhelmed the sound card.  Even putting a 4SLink in line for isolation did not make enough of a difference.

I keyed it and measured about 0.5W from a 9v battery, not too bad.

More observations to follow.

73 Dave NM0S


Re: This morning's Thursday morning net

W0IIT
 

Wayne,

Way to go my friend!!!!! A very good radio tale of victory!!! Nice picture with the story —— it should end up “Somewhere”:-)

cu es 72, Bart W0IIT
Pittsburg, KS
4Sqrp=#72, FP=#11, ARS=#568,
SKCC=1139, NAQCC=#588 FIST=#5819,
Zombie=#500, Geratol=#1000


NAQCC Sprint Wednesday Night

Larry Makoski <w2lj@...>
 

The July sprint is this coming Wednesday evening local time (July 15th,
EDT - 8:30-10:30PM, CDT - 7:30-9:30PM, MDT - 6:30-8:30PM, PDT - 5:30-7:30PM),
which translates as Thursday, July 16th, 0030 to 0230Z in all cases.

For all the "official" information, please go to:

http://naqcc.info/sprint201507.html

There you will find all the details as to time, frequencies and other important
information.

Certificates: SWA (simple wire antennas) certificates by call area, VE and DX
for 1st, 2nd and 3rd place finishers (New!). A Certificate for top score in the
GAIN antenna category.

Prizes: Too many to list!! - check out the prizes page on our website.

This is a monthly event that caters to the CW veteran, the CW newcomer, straight
key and bug fans. All are welcome to participate (this includes QRO); but you
must use QRP power levels to compete for awards.

If you've been hesitant to join in our sprints because you hear other sprints
running at breakneck speeds, have no fear. Our sprints are geared to the
newcomer to CW and/or contesting. Virtually everyone including the many veteran
contesters who regularly enter our sprints will slow down to YOUR speed to help
you make your contacts.

If you are not already a member of NAQCC... membership is FREE! Now is your
chance to join the largest QRP CW Club in the world!! We currently have 7100+
members in: All 50 States - 9 VE Provinces - 100 Countries. Sign up on the
NAQCC website today (http://naqcc.info/) and receive a handsome certificate,
with your membership number on it, which is good for life.

Come join us and have a real good time!

72/73 de Larry W2LJ
NAQCC #35

for NAQCC
http://naqcc.info/


SSS coming up

John Lonigro
 

Don't forget (like I almost did)! The Second Sunday Sprint is this Sunday, from 7:00 - 9:00 pm CDT. We need lots of activity, to make up for the poor showing last month due to the weather. Let's hope the thunderstorms stay away for a few days this month.

72,

John AA0VE
4SQRP Contest Coordinator


Re: 60 mtr rig RM][-60

Chuck Carpenter
 

Converting an RM][-80 to an RM][=60 is on my to-do list. There are some things to consider.

The main consideration in addition to frquency accuracy and stabiltiy and the offset frequency. The offset in the as-designed RMs is not very accurate. RM offset is accomplished with a simple FSK circuit. The offset is intended to be around 600-700 Hz but it rarely is.

Here in the UK, The G-QRP club and Kanga offer crystals for 5MHz. I know that some of our frequencies are the same as US ones.
The crystal frequencies available from Kanga UK are 5373 and 5405.

Failing that, a simple DDS or Si5351 even could provide the correct frequency cheaply and with good stability.
I tried that with a simple DDS vfo. There wasn't enough output so a buffer/amplifier would be needed. But the simple version doesn't have offset capability.

The Arduino or Raspberry, as suggested by Don, would probably be better as the needed offset for the RMs (and other TXs) can be program controlled. They may also need an output amplifier/buffer but that's easily done.

A 5MHz RockMite or 5MHz Kanga FOXX3 (Pixie) would be easy to get going.
Well, maybe not. Specifications for frequency accuracy is plus or minus 50 Hz. This according to International Radio Regulations, although it is not actually specified by the FCC regulations. But, I'd think it needs to be as good any of the modern main stream transceivers on the market.

Getting an RM to have both accurate transmit and offset frequency would required major modifications. I've done this with two rigs on 80 and 30 meters for setting the offset but not for adjusting the oscillator to a precise frequency. With parallel resonant crystals, the RM oscillator frequency is typically 1 to 2 kHz below the marked frequency. With series crystals, just the opposite.

It is possible (I think) to use two variable capacitors in series with the crystal. One to adjust the key-down transmit frequency and the other switched in and out via Q2 for the offset (push button sense too).

Frequency stability may be adequate if the transmitter temperature is controlled. More elaborate schemes may be required.

By this time, it may seem that all the rework is going to cost more than the kit dig... ;-)

If transmit offset is not considered then th receiver needs to accomodate the offset.

Anyway, could be a fun project just to find out what's what!



73, Colin M1BUU



Chuck Carpenter, W5USJ
EM22cv, Rains Co. TX


Re: 60 mtr rig

Colin Evans
 

Curt,

60m is very popular with SOTA ops for NVIS mode contacts.

Here in the UK, The G-QRP club and Kanga offer crystals for 5MHz. I know that some of our frequencies are the same as US ones.

Failing that, a simple DDS or Si5351 even could provide the correct frequency cheaply and with good stability.

A 5MHz RockMite or 5MHz Kanga FOXX3 (Pixie) would be easy to get going.

73, Colin M1BUU


Re: 60 mtr rig

Don Wilhelm <w3fpr@...>
 

Add a mixer - and rather than crystals, use a DDS controlled by a Raspberry Pi.
The RF section from the mixer to the final output is no more difficult than for more simple rigs.  60 meters and 40 meters in the same rig is possible with a low pass filter having a cutoff frequency of 8 to 9 MHz - so the dual band operation is simply a matter of programming.
Add a relay to the LPF to bring the cutoff down to the 6 MHz region and 80 meters could be easily added.
With the mixer already included, it is conceivable to expand it to SSB and DATA mode use as well with just the addition on a balanced modulator and some audio input circuits.

73,
Don W3FPR

On 7/10/2015 8:38 AM, wb8yyy@... [4sqrp] wrote:
 

Interesting idea -- but it has its challenge -- I can't imagine that an appropriate xtal exists, that precisely matches one of the allocated 'channels' in this band, if indeed one can be found to even fall into this band. 

I think I see where you are going -- it might provide some useful propagation when 40m is 'too long.' 


15801 - 15820 of 25075