|
Dear members of QRP Plus Group,
I'm a new comer, Katsuhiko Hirai, just joined to this group.
I got QRP Plus Ver.1 last month.
I'm trying to restart my ham radio hobby after very long QRT since 1985.
It seems for me to be young teen-age days just noticed Ham radio.
I'm going to build my HF antennas soon and modify my QRP Plus,
though my finger playing of CW might be so poor than ever.
Have a nice new day and evening time,
Best regards,
Katsuhiko Hirai
--
Katsuhiko Hirai <mxc04040@...>
in Ikoma, Nara, Japan.
P.E. of Information Technology,
Researcher of the Software Process Engineering,
Amateur Radio Operator: JA3ECA.
--
exN8EYH
|
Katsuhiko San;
Welcome aboard. This is a very slow group. I have not forgotten about it.
It is good to see you here and restarting your ham hobby. Indeed!
I am also restarting in a slow way. I am 65, had a second right cerebral stroke and have learned to walk again. I am still foggy a bit and dizzy at times.
I have 2 QRP+'s one with a companion. One QRP+ is operating correctly, the other, well, after replacing the mixer and powering it up all was well, it was receiving fine..that is until I tried to transmit into a dummy load.. the thing flashed and blew the fuse. Well something else is drastically wrong. I will be troubleshooting it on this blog.
I was a test engineer for Dominion Semiconductor and Toshiba owned it during this time. I spent a lot of time in Japan in the Yokohama area with the manufacturer of a VLSI tester we were purchasing and I was having them modify. The Advantest tester for flash memory devices.. That was over 20 years ago. I miss the engineering.
Anyway I hope this gets to you!
JA3ECA de N1GMM
Guy Mengel N1GMM
|
Dear Guy San/ N1GMM, Good morning to you, I appreciated your checking for my initiation into this mailing-list, QRP Plus group. I'm happy to hear your nice posting under the severe COVID-19. I'm praying your better performance of rehabilitation. In my case, I had been in heart disease, the arrhythmia. Since 2016, I'm free from this by being operated. It's a lucky accident, because a call sign of a friend of mine is JA3GMM, 78yrs old, who got cerebral hemorrhage almost 30 yrs ago. He is still safe now enjoying slow and quiet walks. I'm 76 with my idle activity on the Radio engineering, though I had been a top-highteen operator (so-called junior DXer) with CW on 40m band around 1961 long-long time ago, hi... Today, my finger play is not same as young days performance.....Hi! Last summer, I tried to climb mountains and hills in several weekend. I remembered this QRP+ transceiver which is convenient for my rucksack. I'm going to bring this QRP+ in next summer. I was a computer systems analyst to design operating software, ever. I'm a researcher (maybe hobbyist?!) of the information technology, now. In my U.S. staying days, I got a license of call sign, exN8EYH, in Dayton, Ohio. I had been in Yokohama almost 25 years since 1986. We were staying or working in the same city, ever. You remember a beautiful port of Yokohama at Sunset. Have your nice days, N1GMM de JA3ECA/ Katsuhiko in Nara, _._ _. -- Katsuhiko Hirai <mxc04040@...> in Ikoma, Nara, Japan. P.E. of Information Technology, Researcher of the Software Process Engineering, Amateur Radio Operator: JA3ECA. On Tue, 07 Dec 2021 04:40:00 -0800 "Guy Mengel" <guy@...> wrote: Katsuhiko San;
Welcome aboard. This is a very slow group. I have not forgotten about it.
It is good to see you here and restarting your ham hobby. Indeed!
I am also restarting in a slow way. I am 65, had a second right cerebral stroke and have learned to walk again. I am still foggy a bit and dizzy at times.
I have 2 QRP+'s one with a companion. One QRP+ is operating correctly, the other, well, after replacing the mixer and powering it up all was well, it was receiving fine..that is until I tried to transmit into a dummy load.. the thing flashed and blew the fuse. Well something else is drastically wrong. I will be troubleshooting it on this blog.
I was a test engineer for Dominion Semiconductor and Toshiba owned it during this time. I spent a lot of time in Japan in the Yokohama area with the manufacturer of a VLSI tester we were purchasing and I was having them modify. The Advantest tester for flash memory devices.. That was over 20 years ago. I miss the engineering.
Anyway I hope this gets to you!
JA3ECA de N1GMM
Guy Mengel N1GMM
-- exN8EYH
|
Katsuhiko -- good morning from the UK
I have 2 QRP+ transceivers. One works well the other was purchased to provide spare parts -- which inevitably become 'Unobtanium' over time!
I've repaired a couple of QRP+'s for friends here in the UK. In each case it was the SBL-1 Mixer that had failed.
I did quite a bit of research into why these mixers appear to fail 'spontaneously' and I concluded that it was static electric charge on the antennas so beware when using your 'new' QRP+
Long wires appear to be the worst for this type of failure -- the longer the wire, the more static charge can build up.
I suggest as a precaution you disconnect -- or better still, 'earth' your QRP+ antenna connection when you are not using the rig.
I have a 6-way antenna switch between my QRP rigs and my antennas at home and it enables me to 'earth' any or all the rigs if needed.
There is a small modification you can do to the QRP+ to reduce the likelihood of this failure mode. There is information on the Web about this.
Enjoy your QRP+?
I use mine every week on CW and make many contacts from the UK.
73
Bruce G4ABX
|
What works in dry windy Wyoming, is a 10k resistor across the antenna connector, inside the radio.
The resistor bleeds off the static before it builds up high enough to blow up the mixer. AND it is high enough resistance
to not affect TX operation.?
Have a great day,
Dale - WC7S in Wy
"Actions speak louder than words"
toggle quoted message
Show quoted text
Katsuhiko -- good morning from the UK
I have 2 QRP+ transceivers. One works well the other was purchased to provide spare parts -- which inevitably become 'Unobtanium' over time!
I've repaired a couple of QRP+'s for friends here in the UK. In each case it was the SBL-1 Mixer that had failed.
I did quite a bit of research into why these mixers appear to fail 'spontaneously' and I concluded that it was static electric charge on the antennas so beware when using your 'new' QRP+
Long wires appear to be the worst for this type of failure -- the longer the wire, the more static charge can build up.
I suggest as a precaution you disconnect -- or better still, 'earth' your QRP+ antenna connection when you are not using the rig.
I have a 6-way antenna switch between my QRP rigs and my antennas at home and it enables me to 'earth' any or all the rigs if needed.
There is a small modification you can do to the QRP+ to reduce the likelihood of this failure mode. There is information on the Web about this.
Enjoy your QRP+?
I use mine every week on CW and make many contacts from the UK.
73
Bruce G4ABX
|
Dear Bruce, G4ABX, and DAle, WC7S, Good afternoon to you. It's very fine weather in these days, here in Nara, Japan. I appreciated your posting with supportable good information. I'm still under studying the functionality of circuit diagram in QRP+, as the initial preparation for modification in my summer project. Thanks the message in Dale's posting, "Actions speak louder than words". It encourages me so much. Have a nice weekend, Best regards, Katsuhiko, JA3ECA, exJO1GEG in Yokohama, exN8EYH in Dayton/ OH -- Katsuhiko Hirai <mxc04040@...> in Ikoma, Nara, Japan. P.E. of Information Technology, Researcher of the Software Process Engineering, Amateur Radio Operator: JA3ECA. On Sun, 06 Mar 2022 03:37:17 -0800 "g4abx" <brucemacb@...> wrote: Katsuhiko -- good morning from the UK
I have 2 QRP+ transceivers. One works well the other was purchased to provide spare parts -- which inevitably become 'Unobtanium' over time!
I've repaired a couple of QRP+'s for friends here in the UK. In each case it was the SBL-1 Mixer that had failed.
I did quite a bit of research into why these mixers appear to fail 'spontaneously' and I concluded that it was static electric charge on the antennas so beware when using your 'new' QRP+
Long wires appear to be the worst for this type of failure -- the longer the wire, the more static charge can build up.
I suggest as a precaution you disconnect -- or better still, 'earth' your QRP+ antenna connection when you are not using the rig.
I have a 6-way antenna switch between my QRP rigs and my antennas at home and it enables me to 'earth' any or all the rigs if needed.
There is a small modification you can do to the QRP+ to reduce the likelihood of this failure mode. There is information on the Web about this.
Enjoy your QRP+
I use mine every week on CW and make many contacts from the UK.
73
Bruce G4ABX
-- exN8EYH
|
Good evening Katsu and Dale.
That was the modification I was referring to Dale :-)
You can use any value of resistor you have between say 10K and 30k just soldered across the antenna socket.?
I've done this on my QRP+ and never had a problem with the Mixer since I did the modification.
Katsu. I spent many months in Utsunomiya back in the late 80's when I was working with Honda R&D. I've been to Japan many times since and really enjoyed my stay in your country.
My working life has been in Automotive Electronics -- for 45 years and now I am semi-retired so have time to experiment with Amateur radio again :-)
I've started a Youtube channel for QRP Portable and have a Website and a Twitter account. All this is rather new to me -- but it shows we can all still learn new skills :-)
My 'down time' is spent as a Visiting Professor at my Local University where I help the Post Graduate students with their electronics and software projects. Its great fun passing knowledge to people who really wish to learn :-)
Have fun with your QRP+ and if you have a question, please feel free to email me directly
73
Bruce G4ABX
Youtube: Dr.T(G4ABX)
Web: g4abx.co.uk
Twitter @G4ABX
|
Dear Bruce, G4ABX, and Dale, WC7C, Good morning and good afternoon. 1) Aresting the incoming static electric charge: To Bruce, I appreciated your good idea for the bigger value of resistor to arrest the incoming static electric charge at the antenna connector of tranceiver. Thank you so much, too, Dale. I'll enjoy my procedure to modify my QRP+. 2) Regarding Bruce's experience to stay in Japan: I'm very happy to hear your business experience with Japanese. Several years around 1980, I had lived in Wako city where the Honda headquarter office and Research labo are located. My another hobby is to collect small model engines included micro processor to control fuel flow and heat of cylinder. Have a nice evening, Best regards, Katsuhiko, JA3ECA -- Katsuhiko Hirai <mxc04040@...> in Ikoma, Nara, Japan. P.E. of Information Technology, Researcher of the Software Process Engineering, Amateur Radio Operator: JA3ECA. On Sun, 06 Mar 2022 10:53:53 -0800 "g4abx" <brucemacb@...> wrote: Good evening Katsu and Dale.
That was the modification I was referring to Dale :-)
You can use any value of resistor you have between say 10K and 30k just soldered across the antenna socket.
I've done this on my QRP+ and never had a problem with the Mixer since I did the modification.
Katsu. I spent many months in Utsunomiya back in the late 80's when I was working with Honda R&D. I've been to Japan many times since and really enjoyed my stay in your country.
My working life has been in Automotive Electronics -- for 45 years and now I am semi-retired so have time to experiment with Amateur radio again :-)
I've started a Youtube channel for QRP Portable and have a Website and a Twitter account. All this is rather new to me -- but it shows we can all still learn new skills :-)
My 'down time' is spent as a Visiting Professor at my Local University where I help the Post Graduate students with their electronics and software projects. Its great fun passing knowledge to people who really wish to learn :-)
Have fun with your QRP+ and if you have a question, please feel free to email me directly
73
Bruce G4ABX
Youtube: Dr.T(G4ABX)
Web: g4abx.co.uk
Twitter @G4ABX
-- exN8EYH
|
Hi Katsu San; Guy here.? The resistors will work as well as some back to back 1N914 diodes on the Antenna input.? There are a few articles Here: I have his original QRP PLUS and external noise bridge.? As well as a second QRP +.? Both work great but are now offline. Anyway, if you need any help let me know.? I have repaired several of these machines.? There is a newer QRP++ that has a custom mixer and circuitry (Rev 2) that you may have as well.? They no longer make the newer Mixer..
Hope all is well Guy
On Mon, Mar 7, 2022 at 10:06 AM Katsu. Hirai < mxc04040@...> wrote: Dear Bruce, G4ABX, and Dale, WC7C,
Good morning and good afternoon.
1) Aresting the incoming static electric charge:
To Bruce, I appreciated your good idea for the bigger value of resistor
to arrest the incoming static electric charge at the antenna connector
of tranceiver.
Thank you so much, too, Dale.
I'll enjoy my procedure to modify my QRP+.
2) Regarding Bruce's experience to stay in Japan:
I'm very happy to hear your business experience with Japanese.
Several years around 1980, I had lived in Wako city where the Honda
headquarter office and Research labo are located.
My another hobby is to collect small model engines included micro
processor to control fuel flow and heat of cylinder.
Have a nice evening,
Best regards,
Katsuhiko, JA3ECA
--
Katsuhiko Hirai <mxc04040@...>
in Ikoma, Nara, Japan.
P.E. of Information Technology,?
Researcher of the Software Process Engineering,
Amateur Radio Operator: JA3ECA.
On Sun, 06 Mar 2022 10:53:53 -0800
"g4abx" <brucemacb@...> wrote:
> Good evening Katsu and Dale.
> That was the modification I was referring to Dale :-)
>
> You can use any value of resistor you have between say 10K and 30k just soldered across the antenna socket.
> I've done this on my QRP+ and never had a problem with the Mixer since I did the modification.
>
> Katsu. I spent many months in Utsunomiya back in the late 80's when I was working with Honda R&D. I've been to Japan many times since and really enjoyed my stay in your country.
> My working life has been in Automotive Electronics -- for 45 years and now I am semi-retired so have time to experiment with Amateur radio again :-)
> I've started a Youtube channel for QRP Portable and have a Website and a Twitter account. All this is rather new to me -- but it shows we can all still learn new skills :-)
>
> My 'down time' is spent as a Visiting Professor at my Local University where I help the Post Graduate students with their electronics and software projects. Its great fun passing knowledge to people who really wish to learn :-)
>
> Have fun with your QRP+ and if you have a question, please feel free to email me directly
>
> 73
> Bruce G4ABX
>
> Youtube: Dr.T(G4ABX)
> Web:
> Twitter @G4ABX
>
>
>
>
>
--
exN8EYH
-- N1GMM
Slower than a snail with a sore back! Be Patient with me.
Guy Mengel
[old and will be going away]
[NEW!]
guy@...
-.-. --.- -.-. --.- -.. .
\|%|///
| ~ ~ |
^( @ @ )^
---------o000o--_/-o000o---------
N1GMM
|
Dear Guy, N1GMM and group Good morning to you. I appreciated your nice posting for my modification plan. I'm so happy to hear your note. How are your health condition? Yesterday, I met my doctor for checking my health inspection. My doctor suggested me fortunately to continue my daily life to enjoy getting meal, walking hills and valley, studying computer software and radio mechanism. Thank you for your information of URL for the modification into QRP+. I'll enjoy to check them and study their ideas. Have a nice new day, Best regards, Katsuhiko, JA3ECA -- Katsuhiko Hirai <mxc04040@...> in Ikoma, Nara, Japan. P.E. of Information Technology, Researcher of the Software Process Engineering, Amateur Radio Operator: JA3ECA. On Mon, 7 Mar 2022 10:38:59 -0500 "Guy Mengel N1GMM" <guy@...> wrote: Hi Katsu San;
Guy here. The resistors will work as well as some back to back 1N914
diodes on the Antenna input. There are a few articles Here:
I have his original QRP PLUS and external noise bridge. As well as a
second QRP +. Both work great but are now offline.
Anyway, if you need any help let me know. I have repaired several of these
machines. There is a newer QRP++ that has a custom mixer and circuitry
(Rev 2) that you may have as well. They no longer make the newer Mixer..
Hope all is well
Guy
On Mon, Mar 7, 2022 at 10:06 AM Katsu. Hirai <mxc04040@...> wrote:
Dear Bruce, G4ABX, and Dale, WC7C,
Good morning and good afternoon.
1) Aresting the incoming static electric charge:
To Bruce, I appreciated your good idea for the bigger value of resistor
to arrest the incoming static electric charge at the antenna connector
of tranceiver.
Thank you so much, too, Dale.
I'll enjoy my procedure to modify my QRP+.
2) Regarding Bruce's experience to stay in Japan:
I'm very happy to hear your business experience with Japanese.
Several years around 1980, I had lived in Wako city where the Honda
headquarter office and Research labo are located.
My another hobby is to collect small model engines included micro
processor to control fuel flow and heat of cylinder.
Have a nice evening,
Best regards,
Katsuhiko, JA3ECA
--
Katsuhiko Hirai <mxc04040@...>
in Ikoma, Nara, Japan.
P.E. of Information Technology,
Researcher of the Software Process Engineering,
Amateur Radio Operator: JA3ECA.
On Sun, 06 Mar 2022 10:53:53 -0800
"g4abx" <brucemacb@...> wrote:
Good evening Katsu and Dale.
That was the modification I was referring to Dale :-)
You can use any value of resistor you have between say 10K and 30k just soldered across the antenna socket.
I've done this on my QRP+ and never had a problem with the Mixer since I did the modification.
Katsu. I spent many months in Utsunomiya back in the late 80's when I
was working with Honda R&D. I've been to Japan many times since and really
enjoyed my stay in your country.
My working life has been in Automotive Electronics -- for 45 years and now I am semi-retired so have time to experiment with Amateur radio again
:-)
I've started a Youtube channel for QRP Portable and have a Website and a Twitter account. All this is rather new to me -- but it shows we can all
still learn new skills :-)
My 'down time' is spent as a Visiting Professor at my Local University
where I help the Post Graduate students with their electronics and software
projects. Its great fun passing knowledge to people who really wish to
learn :-)
Have fun with your QRP+ and if you have a question, please feel free to
email me directly
73
Bruce G4ABX
Youtube: Dr.T(G4ABX)
Web: g4abx.co.uk
Twitter @G4ABX
--
exN8EYH
--
N1GMM
Slower than a snail with a sore back! Be Patient with me.
Guy Mengel
[old and will be going away]
[NEW!]
guy@...
-.-. --.- -.-. --.- -.. .
\|%|///
| ~ ~ |
^( @ @ )^
---------o000o--_/-o000o---------
N1GMM
-- exN8EYH
|
The back to back diodes across the antenna input, will work without an issue, as long as NO TRANSMISSIONS are made.?
The issue becomes the back to back diodes may cause interference to other radios and cause the tx to become very unclean with
spurious rf generated. The resistor bleeds off the static, without any issues during tx, because it is such a high impedance.?
Have a great day,
Dale - WC7S in Wy
"Actions speak louder than words"
toggle quoted message
Show quoted text
Dear Guy, N1GMM and group
Good morning to you.
I appreciated your nice posting for my modification plan.
I'm so happy to hear your note.
How are your health condition?
Yesterday, I met my doctor for checking my health inspection.
My doctor suggested me fortunately to continue my daily life to
enjoy getting meal, walking hills and valley, studying computer software
and radio mechanism.
Thank you for your information of URL for the modification into QRP+.
I'll enjoy to check them and study their ideas.
Have a nice new day,
Best regards,
Katsuhiko, JA3ECA
--
Katsuhiko Hirai <mxc04040@...>
in Ikoma, Nara, Japan.
P.E. of Information Technology,?
Researcher of the Software Process Engineering,
Amateur Radio Operator: JA3ECA.
On Mon, 7 Mar 2022 10:38:59 -0500
"Guy Mengel N1GMM" <guy@...> wrote:
> Hi Katsu San;
> Guy here.? The resistors will work as well as some back to back 1N914
> diodes on the Antenna input.? There are a few articles Here:
>
> I have his original QRP PLUS and external noise bridge.? As well as a
> second QRP +.? Both work great but are now offline.
> Anyway, if you need any help let me know.? I have repaired several of these
> machines.? There is a newer QRP++ that has a custom mixer and circuitry
> (Rev 2) that you may have as well.? They no longer make the newer Mixer..
>
> Hope all is well
> Guy
>
> On Mon, Mar 7, 2022 at 10:06 AM Katsu. Hirai <mxc04040@...> wrote:
>
> > Dear Bruce, G4ABX, and Dale, WC7C,
> > Good morning and good afternoon.
> >
> > 1) Aresting the incoming static electric charge:
> > To Bruce, I appreciated your good idea for the bigger value of resistor
> > to arrest the incoming static electric charge at the antenna connector
> > of tranceiver.
> > Thank you so much, too, Dale.
> > I'll enjoy my procedure to modify my QRP+.
> >
> > 2) Regarding Bruce's experience to stay in Japan:
> > I'm very happy to hear your business experience with Japanese.
> > Several years around 1980, I had lived in Wako city where the Honda
> > headquarter office and Research labo are located.
> >
> > My another hobby is to collect small model engines included micro
> > processor to control fuel flow and heat of cylinder.
> >
> > Have a nice evening,
> > Best regards,
> > Katsuhiko, JA3ECA
> > --
> > Katsuhiko Hirai <mxc04040@...>
> > in Ikoma, Nara, Japan.
> > P.E. of Information Technology,
> > Researcher of the Software Process Engineering,
> > Amateur Radio Operator: JA3ECA.
> >
> > On Sun, 06 Mar 2022 10:53:53 -0800
> > "g4abx" <brucemacb@...> wrote:
> >
> > > Good evening Katsu and Dale.
> > > That was the modification I was referring to Dale :-)
> > >
> > > You can use any value of resistor you have between say 10K and 30k just
> > soldered across the antenna socket.
> > > I've done this on my QRP+ and never had a problem with the Mixer since I
> > did the modification.
> > >
> > > Katsu. I spent many months in Utsunomiya back in the late 80's when I
> > was working with Honda R&D. I've been to Japan many times since and really
> > enjoyed my stay in your country.
> > > My working life has been in Automotive Electronics -- for 45 years and
> > now I am semi-retired so have time to experiment with Amateur radio again
> > :-)
> > > I've started a Youtube channel for QRP Portable and have a Website and a
> > Twitter account. All this is rather new to me -- but it shows we can all
> > still learn new skills :-)
> > >
> > > My 'down time' is spent as a Visiting Professor at my Local University
> > where I help the Post Graduate students with their electronics and software
> > projects. Its great fun passing knowledge to people who really wish to
> > learn :-)
> > >
> > > Have fun with your QRP+ and if you have a question, please feel free to
> > email me directly
> > >
> > > 73
> > > Bruce G4ABX
> > >
> > > Youtube: Dr.T(G4ABX)
> > > Web: g4abx.co.uk
> > > Twitter @G4ABX
> > >
> > >
> > >
> > >
> > >
> >
> >
> >
> > --
> > exN8EYH
> >
> >
> >
> >
> >
> >
>
> --
>
> N1GMM
> Slower than a snail with a sore back!? Be Patient with me.
> Guy Mengelhttps://www.qrz.com/db/N1GMMhttps://niggles-parish.blogspot.com/
> [old and will be going away]
> [NEW!]
> guy@...
>
> -.-. --.- -.-. --.- -.. .
>????????????? \|%|///
>????????????? | ~ ~ |
>???????????? ^( @ @ )^
> ---------o000o--_/-o000o---------
> N1GMM
>
>
>
>
>
--
exN8EYH
|
Hi Dale, Thanks! I have had QRP +'s for many years.. still have 2 one with the external noisebridge and tuner. QRP+'s are not without many issues indeed, but fun to use! First, I have no mods installed (yet).. I unplug antenna after any use. Second, Mixer problems and blowups are/were a common affair. I have fixed several and these are getting harder to fix as parts are really not available for some things.. I am sure Larry W1HUE would not mind this re-posting from 1996 " From Larry East, W1HUE, on 04 Apr, 1996 I just can't help but comment on this: A couple of back to back zeners might be cheap insurance for the older design 'QRP plus' receiver front ends as well, that seem to fail on antenna static buildup; although high ohm resistors would likely do as well. A diode after all, on a receiver front end is another detector, and that might cause an occasional concern. Putting them back to back in series keeps the forward junction direction from conducting, unless a REALLY big signal sets up next door! First of all, there is already a resistance path from the antenna input to ground in the QRP+: R15 and R16 (about 2.5K total) which make up the divider to the ALC detector. This DOES NOT offer protection to the input mixer from big static discharges (100V across 2.5K is only 40mA after all...). To protect the input mixer, install four diodes right after C49 on the RF board as follows: C49 |------|<---|<----| >---||-----| |---Gnd. |------>|--->|----| | | |---> to rcv/xmit relay The diodes should be low capacity switching types, such as 1N914/1N4148. Do NOT use Shottky or PIN diodes. The two diodes in series in each leg reduce the chance of creating potential intermod problems on strong signals. I would NOT recommend back-to-back zeniers because of their capacitance (*), although low power (<1W) low voltage types (3-5V) might work OK. The diodes can be mounted on the bottom of the RF board, taking care not to short them to any solder pads. In the "new improved" QRP+, Index has installed a varistor at this same point to protect the mixer; I don't know the actual type, but I suspect that it must have a breakdown voltage of less than 10V in order to be effective. A properly chosen varistor could probably handle a much larger surge current than the diode scheme shown above and not add a significant amount of capacitance -- does anyone know what type Index uses? (I don't have much success getting such info from Index directly... Bruce is always busy or otherwise unavailable and he or his service tech never return my calls.) (*) "Why is the capacitance not a problem when a zenier is used to protect a transmitter output transistor?" you might well ask. It is because in the transmitter application, the zenier is reverse biased thereby reducing its junction capacitance. The zero-bias junction capacitance of a 1W zenier is 50+ pF and drops to 10-15 pF when a reverse bias of 10-12V is applied. The zero bias junction capacitance of a 1N4148 (or similar) switching diode, on the other hand, is only 1- 2pF. " These are just some coments from: on line. I have his original unit that he used in these comments... works like a charm with no mods (UNPLUG) the antenna! Hope you have a fine day! 73 Guy N1GMM On Wed, 2022-03-09 at 13:59 +0000, Dale Putnam wrote: The back to back diodes across the antenna input, will work without
an issue, as long as NO TRANSMISSIONS are made.?
The issue becomes the back to back diodes may cause interference to
other radios and cause the tx to become very unclean with
spurious rf generated. The resistor bleeds off the static, without
any issues during tx, because it is such a high impedance.?
Have a great day,
Dale - WC7S in Wy
"Actions speak louder than words"
From: [email protected] <[email protected]> on behalf of Katsu. Hirai
<mxc04040@...>
Sent: Wednesday, March 9, 2022 5:30 AM
To: [email protected] <[email protected]>
Subject: Re: [QRPPlus] Good morning and good evening to all?
Dear Guy, N1GMM and group
Good morning to you.
I appreciated your nice posting for my modification plan.
I'm so happy to hear your note.
How are your health condition?
Yesterday, I met my doctor for checking my health inspection.
My doctor suggested me fortunately to continue my daily life to
enjoy getting meal, walking hills and valley, studying computer
software
and radio mechanism.
Thank you for your information of URL for the modification into QRP+.
I'll enjoy to check them and study their ideas.
Have a nice new day,
Best regards,
Katsuhiko, JA3ECA
--
Katsuhiko Hirai <mxc04040@...>
in Ikoma, Nara, Japan.
P.E. of Information Technology,?
Researcher of the Software Process Engineering,
Amateur Radio Operator: JA3ECA.
On Mon, 7 Mar 2022 10:38:59 -0500
"Guy Mengel N1GMM" <guy@...> wrote:
Hi Katsu San;
Guy here.? The resistors will work as well as some back to back
1N914
diodes on the Antenna input.? There are a few articles Here:
I have his original QRP PLUS and external noise bridge.? As well as
a
second QRP +.? Both work great but are now offline.
Anyway, if you need any help let me know.? I have repaired several
of these
machines.? There is a newer QRP++ that has a custom mixer and
circuitry
(Rev 2) that you may have as well.? They no longer make the newer
Mixer..
Hope all is well
Guy
On Mon, Mar 7, 2022 at 10:06 AM Katsu. Hirai <mxc04040@...>
wrote:
Dear Bruce, G4ABX, and Dale, WC7C,
Good morning and good afternoon.
1) Aresting the incoming static electric charge:
To Bruce, I appreciated your good idea for the bigger value of
resistor
to arrest the incoming static electric charge at the antenna
connector
of tranceiver.
Thank you so much, too, Dale.
I'll enjoy my procedure to modify my QRP+.
2) Regarding Bruce's experience to stay in Japan:
I'm very happy to hear your business experience with Japanese.
Several years around 1980, I had lived in Wako city where the
Honda
headquarter office and Research labo are located.
My another hobby is to collect small model engines included micro
processor to control fuel flow and heat of cylinder.
Have a nice evening,
Best regards,
Katsuhiko, JA3ECA
--
Katsuhiko Hirai <mxc04040@...>
in Ikoma, Nara, Japan.
P.E. of Information Technology,
Researcher of the Software Process Engineering,
Amateur Radio Operator: JA3ECA.
On Sun, 06 Mar 2022 10:53:53 -0800
"g4abx" <brucemacb@...> wrote:
Good evening Katsu and Dale.
That was the modification I was referring to Dale :-)
You can use any value of resistor you have between say 10K and
30k just soldered across the antenna socket.
I've done this on my QRP+ and never had a problem with the
Mixer since I did the modification.
Katsu. I spent many months in Utsunomiya back in the late 80's
when I
was working with Honda R&D. I've been to Japan many times since
and really
enjoyed my stay in your country.
My working life has been in Automotive Electronics -- for 45
years and now I am semi-retired so have time to experiment with Amateur
radio again
:-)
I've started a Youtube channel for QRP Portable and have a
Website and a Twitter account. All this is rather new to me -- but it shows we
can all
still learn new skills :-)
My 'down time' is spent as a Visiting Professor at my Local
University
where I help the Post Graduate students with their electronics
and software
projects. Its great fun passing knowledge to people who really
wish to
learn :-)
Have fun with your QRP+ and if you have a question, please feel
free to
email me directly
73
Bruce G4ABX
Youtube: Dr.T(G4ABX)
Web: g4abx.co.uk
Twitter @G4ABX
--
exN8EYH
--
N1GMM
Slower than a snail with a sore back!? Be Patient with me.
Guy
Mengel
om/
[old and will be going away]
[NEW!]
guy@...
-.-. --.- -.-. --.- -.. .
????????????? \|%|///
????????????? | ~ ~ |
???????????? ^( @ @ )^
---------o000o--_/-o000o---------
N1GMM
|
Hi Dale,
One more thing. I have only "seen" the new version 2 changes made with
new special mixer one time. I did purchase a broken unit which "said"
it was version 2, but no it was a mix of boards, the RF board had been
switched to the older version and had been hacked on.. it is fixed now
:-) and the mixer and finals replaced. But the VR1 you speak of is an
interesting fix. I would love to see if I could find out what it was.
I have the new insert schematic for the RF board. But it does not say
what VR1 is.. Some hunting. this is fun!
I am not sure I can post the schematics here..
Guy
toggle quoted message
Show quoted text
On Wed, 2022-03-09 at 09:18 -0500, guy@... wrote:
Hi Dale,
Thanks!? I have had QRP +'s for many years.. still have 2 one with
the
external noisebridge and tuner.? QRP+'s are not without many issues
indeed, but fun to use!
First, I have no mods installed (yet).. I unplug antenna after any
use.
Second, Mixer problems and blowups are/were a common affair.? I have
fixed several and these are getting harder to fix as parts are really
not available for some things..
I am sure Larry W1HUE would not mind this re-posting from 1996
"? From Larry East, W1HUE, on 04 Apr, 1996
??? I just can't help but comment on this:
??????? A couple of back to back zeners might be cheap insurance for
the older design 'QRP plus' receiver front ends as well, that seem to
fail on antenna static buildup; although high ohm resistors would
likely do as well. A diode after all, on a receiver front end is
another detector, and that might cause an occasional concern. Putting
them back to back in series keeps the forward junction direction from
conducting, unless a REALLY big signal sets up next door!
??? First of all, there is already a resistance path from the antenna
input to ground in the QRP+: R15 and R16 (about 2.5K total) which
make
up the divider to the ALC detector. This DOES NOT offer protection to
the input mixer from big static discharges (100V across 2.5K is only
40mA after all...). To protect the input mixer, install four diodes
right after C49 on the RF board as follows:
???????????? C49??? |------|<---|<----|
???????? >---||-----|???????????????? |---Gnd.
??????????????????? |------>|--->|----|
??????????????????? |
??????????????????? |
??????????????????? |---> to rcv/xmit relay
????????
??? The diodes should be low capacity switching types, such as
1N914/1N4148. Do NOT use Shottky or PIN diodes. The two diodes in
series in each leg reduce the chance of creating potential intermod
problems on strong signals. I would NOT recommend back-to-back
zeniers
because of their capacitance (*), although low power (<1W) low
voltage
types (3-5V) might work OK. The diodes can be mounted on the bottom
of
the RF board, taking care not to short them to any solder pads.
??? In the "new improved" QRP+, Index has installed a varistor at
this
same point to protect the mixer; I don't know the actual type, but I
suspect that it must have a breakdown voltage of less than 10V in
order
to be effective. A properly chosen varistor could probably handle a
much larger surge current than the diode scheme shown above and not
add
a significant amount of capacitance -- does anyone know what type
Index
uses? (I don't have much success getting such info from Index
directly... Bruce is always busy or otherwise unavailable and he or
his
service tech never return my calls.)
??? (*) "Why is the capacitance not a problem when a zenier is used
to
protect a transmitter output transistor?" you might well ask. It is
because in the transmitter application, the zenier is reverse biased
thereby reducing its junction capacitance. The zero-bias junction
capacitance of a 1W zenier is 50+ pF and drops to 10-15 pF when a
reverse bias of 10-12V is applied. The zero bias junction capacitance
of a 1N4148 (or similar) switching diode, on the other hand, is only
1-
2pF.
"
These are just some coments from:
on line.? I have his original unit that he used in these comments...
works like a charm with no mods (UNPLUG) the antenna!
Hope you have a fine day!
73 Guy N1GMM
On Wed, 2022-03-09 at 13:59 +0000, Dale Putnam wrote:
The back to back diodes across the antenna input, will work without
an issue, as long as NO TRANSMISSIONS are made.?
The issue becomes the back to back diodes may cause interference to
other radios and cause the tx to become very unclean with
spurious rf generated. The resistor bleeds off the static, without
any issues during tx, because it is such a high impedance.?
Have a great day,
Dale - WC7S in Wy
"Actions speak louder than words"
From: [email protected]?<[email protected]> on behalf of Katsu.
Hirai
<mxc04040@...>
Sent: Wednesday, March 9, 2022 5:30 AM
To: [email protected]?<[email protected]>
Subject: Re: [QRPPlus] Good morning and good evening to all?
Dear Guy, N1GMM and group
Good morning to you.
I appreciated your nice posting for my modification plan.
I'm so happy to hear your note.
How are your health condition?
Yesterday, I met my doctor for checking my health inspection.
My doctor suggested me fortunately to continue my daily life to
enjoy getting meal, walking hills and valley, studying computer
software
and radio mechanism.
Thank you for your information of URL for the modification into
QRP+.
I'll enjoy to check them and study their ideas.
Have a nice new day,
Best regards,
Katsuhiko, JA3ECA
--
Katsuhiko Hirai <mxc04040@...>
in Ikoma, Nara, Japan.
P.E. of Information Technology,?
Researcher of the Software Process Engineering,
Amateur Radio Operator: JA3ECA.
On Mon, 7 Mar 2022 10:38:59 -0500
"Guy Mengel N1GMM" <guy@...> wrote:
Hi Katsu San;
Guy here.? The resistors will work as well as some back to back
1N914
diodes on the Antenna input.? There are a few articles Here:
I have his original QRP PLUS and external noise bridge.? As well
as
a
second QRP +.? Both work great but are now offline.
Anyway, if you need any help let me know.? I have repaired
several
of these
machines.? There is a newer QRP++ that has a custom mixer and
circuitry
(Rev 2) that you may have as well.? They no longer make the newer
Mixer..
Hope all is well
Guy
On Mon, Mar 7, 2022 at 10:06 AM Katsu. Hirai
<mxc04040@...>
wrote:
Dear Bruce, G4ABX, and Dale, WC7C,
Good morning and good afternoon.
1) Aresting the incoming static electric charge:
To Bruce, I appreciated your good idea for the bigger value of
resistor
to arrest the incoming static electric charge at the antenna
connector
of tranceiver.
Thank you so much, too, Dale.
I'll enjoy my procedure to modify my QRP+.
2) Regarding Bruce's experience to stay in Japan:
I'm very happy to hear your business experience with Japanese.
Several years around 1980, I had lived in Wako city where the
Honda
headquarter office and Research labo are located.
My another hobby is to collect small model engines included
micro
processor to control fuel flow and heat of cylinder.
Have a nice evening,
Best regards,
Katsuhiko, JA3ECA
--
Katsuhiko Hirai <mxc04040@...>
in Ikoma, Nara, Japan.
P.E. of Information Technology,
Researcher of the Software Process Engineering,
Amateur Radio Operator: JA3ECA.
On Sun, 06 Mar 2022 10:53:53 -0800
"g4abx" <brucemacb@...> wrote:
Good evening Katsu and Dale.
That was the modification I was referring to Dale :-)
You can use any value of resistor you have between say 10K
and
30k just soldered across the antenna socket.
I've done this on my QRP+ and never had a problem with the
Mixer since I did the modification.
Katsu. I spent many months in Utsunomiya back in the late
80's
when I
was working with Honda R&D. I've been to Japan many times since
and really
enjoyed my stay in your country.
My working life has been in Automotive Electronics -- for 45
years and now I am semi-retired so have time to experiment with Amateur
radio again
:-)
I've started a Youtube channel for QRP Portable and have a
Website and a Twitter account. All this is rather new to me -- but it shows
we
can all
still learn new skills :-)
My 'down time' is spent as a Visiting Professor at my Local
University
where I help the Post Graduate students with their electronics
and software
projects. Its great fun passing knowledge to people who really
wish to
learn :-)
Have fun with your QRP+ and if you have a question, please
feel
free to
email me directly
73
Bruce G4ABX
Youtube: Dr.T(G4ABX)
Web: g4abx.co.uk
Twitter @G4ABX
--
exN8EYH
--
N1GMM
Slower than a snail with a sore back!? Be Patient with me.
Guy
Mengel
om/
[old and will be going away]
[NEW!]
guy@...
-.-. --.- -.-. --.- -.. .
????????????? \|%|///
????????????? | ~ ~ |
???????????? ^( @ @ )^
---------o000o--_/-o000o---------
N1GMM
|
Katsu. Hirai
Guy Mengel N1GMM
g4abx