Date   
Re: Using Vacuum Tube heathkit as Linear Amplifier for QRP

James Lynes
 

Yes it did. I read it last night. I believe the same info is on the qrp labs website in the qsx area.

James

Re: Using Vacuum Tube heathkit as Linear Amplifier for QRP

Bill Cromwell
 

Hi Richard,

I copied the whole thing from one of the ARRL Handbooks. I'm sure I can find it again. I will have a look. I do still have the T-R switch and maybe even the coupling capacitor. That cap is a "gimmick" made from about three inches of RG-58. Don't let the "gimmick" label throw you over. It is more than a little twisted pair as sometimes used in receiver circuits for regenerative feedback.

I built mine in an old TV tuner metal box. I don't know what they have in TV sets for a tuner these days but I think it is an SDR front-end. An Altoids tin (or something similar) would work. The transistor is a 40673 dual gate mosfet and is now just about unobtanium. Fortunately there are plentiful substitutes. You could also use a vacuum tube <grin>.

More later after I dig out the details. It is so easy that even *I* could do it.

73,

Bill KU8H

On 11/12/19 4:07 PM, Richard Spohn wrote:
Bill, do you have the schematic for the solid-state T/R switch, or
even better, do you still have that switch? I am keenly interested in
an all-electronic (no relays) T/R switch for QSK. Building one from
scratch may be slightly outside my skill set tho. -- Rich WB2GXM
--
bark less - wag more

Re: Using Vacuum Tube heathkit as Linear Amplifier for QRP

Jack, W8TEE
 

Didn't Hans QSX talk at FDIM and reprinted in QRPQ (October issue??) discuss a "relayless" TR switch?

Jack, W8TEE

On Tuesday, November 12, 2019, 4:08:07 PM EST, Richard Spohn <wb2gxm@...> wrote:


Bill, do you have the schematic for the solid-state T/R switch, or
even better, do you still have that switch?  I am keenly interested in
an all-electronic (no relays) T/R switch for QSK.  Building one from
scratch may be slightly outside my skill set tho. -- Rich WB2GXM

On 11/10/19, Bill Cromwell <wrcromwell@...> wrote:
> Hi,
>
> In the 80s I built boots for an Ten Tec Argonaut 509 using the carcass
> of a Heathkit DX-35. There is no receive circuitry involved. I biased
> the single 6146 for class AB1 operation. I built a solid state T-R
> antenna switch to keep the QSK feature of the 509. It served me for a
> several years and then the 509 moved to a new home. The remains of the
> DX-35 also went to another ham.
>
> I have the CW portion of a Heathkit DX-100 down for overhaul. The AM
> phone parts were all gone when I got the DX-100. I am going to dpo the
> mods to include the linear operation in phone mode to amplify SSB
> signals and keep the class C operation for it's CW operation - ala the
> Apache (TX-1). Grid block keying has already been part of this
> particular DX-100.
>
> Sometimes QRP is just not enough.
>
> 73,
>
> Bill  KU8H
>
> On 11/10/19 7:35 AM, Don Richards wrote:
>> Hi Gordon
>> I ran across this a while back but never tried it.
>>
>> https://www.google.com/url?sa=t&source=web&rct=j&url=https://frrl.files.wordpress.com/2008/09/hotwaterforthek2.pdf&ved=2ahUKEwjwzsTQ09_lAhWsmuAKHQ1MCyYQFjACegQIARAB&usg=AOvVaw1PdjqVxSUEw-wayoqwuZyO
>>
>> 73 Donve3ids
>
> --
> bark less - wag more
>
>
>
>




--
Jack, W8TEE

Re: Using Vacuum Tube heathkit as Linear Amplifier for QRP

Richard Spohn
 

MFJ "Pin Diode Rig"....a model or part number?

On 11/12/19, Gordon Gibby <docvacuumtubes@...> wrote:
There is this MFJ pin diode rig that I managed to pick up on ebay for
$100. You might look around for another of those. They do take some
tinkering I'm told.

An even easier solution is to simply emulate the HW-16 and have TWO devices
--- one used for transmit and one used for receive -- and control both of
them with the same digitally created frequency (from a Raduino) and just
use diode protection of the input of the "receiver" just as many qrp rigs
do. There are probably a lot of schematics out there for creating a
diode switch also.

Gordon


On Tue, Nov 12, 2019 at 4:08 PM Richard Spohn <wb2gxm@...> wrote:

Bill, do you have the schematic for the solid-state T/R switch, or
even better, do you still have that switch? I am keenly interested in
an all-electronic (no relays) T/R switch for QSK. Building one from
scratch may be slightly outside my skill set tho. -- Rich WB2GXM

On 11/10/19, Bill Cromwell <wrcromwell@...> wrote:
Hi,

In the 80s I built boots for an Ten Tec Argonaut 509 using the carcass
of a Heathkit DX-35. There is no receive circuitry involved. I biased
the single 6146 for class AB1 operation. I built a solid state T-R
antenna switch to keep the QSK feature of the 509. It served me for a
several years and then the 509 moved to a new home. The remains of the
DX-35 also went to another ham.

I have the CW portion of a Heathkit DX-100 down for overhaul. The AM
phone parts were all gone when I got the DX-100. I am going to dpo the
mods to include the linear operation in phone mode to amplify SSB
signals and keep the class C operation for it's CW operation - ala the
Apache (TX-1). Grid block keying has already been part of this
particular DX-100.

Sometimes QRP is just not enough.

73,

Bill KU8H

On 11/10/19 7:35 AM, Don Richards wrote:
Hi Gordon
I ran across this a while back but never tried it.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://frrl.files.wordpress.com/2008/09/hotwaterforthek2.pdf&ved=2ahUKEwjwzsTQ09_lAhWsmuAKHQ1MCyYQFjACegQIARAB&usg=AOvVaw1PdjqVxSUEw-wayoqwuZyO

73 Donve3ids
--
bark less - wag more







Re: Using Vacuum Tube heathkit as Linear Amplifier for QRP

Gordon Gibby
 

There is this MFJ pin diode rig that I managed to pick up on ebay for $100.   You might look around for another of those.   They do take some tinkering I'm told.    

An even easier solution is to simply emulate the HW-16 and have TWO devices --- one used for transmit and one used for receive -- and control both of them with the same digitally created frequency (from a Raduino) and just use diode protection of the input of the "receiver" just as many qrp rigs do.    There are probably a lot of schematics out there for creating a diode switch also.   

Gordon


On Tue, Nov 12, 2019 at 4:08 PM Richard Spohn <wb2gxm@...> wrote:
Bill, do you have the schematic for the solid-state T/R switch, or
even better, do you still have that switch?  I am keenly interested in
an all-electronic (no relays) T/R switch for QSK.  Building one from
scratch may be slightly outside my skill set tho. -- Rich WB2GXM

On 11/10/19, Bill Cromwell <wrcromwell@...> wrote:
> Hi,
>
> In the 80s I built boots for an Ten Tec Argonaut 509 using the carcass
> of a Heathkit DX-35. There is no receive circuitry involved. I biased
> the single 6146 for class AB1 operation. I built a solid state T-R
> antenna switch to keep the QSK feature of the 509. It served me for a
> several years and then the 509 moved to a new home. The remains of the
> DX-35 also went to another ham.
>
> I have the CW portion of a Heathkit DX-100 down for overhaul. The AM
> phone parts were all gone when I got the DX-100. I am going to dpo the
> mods to include the linear operation in phone mode to amplify SSB
> signals and keep the class C operation for it's CW operation - ala the
> Apache (TX-1). Grid block keying has already been part of this
> particular DX-100.
>
> Sometimes QRP is just not enough.
>
> 73,
>
> Bill  KU8H
>
> On 11/10/19 7:35 AM, Don Richards wrote:
>> Hi Gordon
>> I ran across this a while back but never tried it.
>>
>> https://www.google.com/url?sa=t&source=web&rct=j&url=https://frrl.files.wordpress.com/2008/09/hotwaterforthek2.pdf&ved=2ahUKEwjwzsTQ09_lAhWsmuAKHQ1MCyYQFjACegQIARAB&usg=AOvVaw1PdjqVxSUEw-wayoqwuZyO
>>
>> 73 Donve3ids
>
> --
> bark less - wag more
>
>
>
>



Re: Using Vacuum Tube heathkit as Linear Amplifier for QRP

Richard Spohn
 

Bill, do you have the schematic for the solid-state T/R switch, or
even better, do you still have that switch? I am keenly interested in
an all-electronic (no relays) T/R switch for QSK. Building one from
scratch may be slightly outside my skill set tho. -- Rich WB2GXM

On 11/10/19, Bill Cromwell <wrcromwell@...> wrote:
Hi,

In the 80s I built boots for an Ten Tec Argonaut 509 using the carcass
of a Heathkit DX-35. There is no receive circuitry involved. I biased
the single 6146 for class AB1 operation. I built a solid state T-R
antenna switch to keep the QSK feature of the 509. It served me for a
several years and then the 509 moved to a new home. The remains of the
DX-35 also went to another ham.

I have the CW portion of a Heathkit DX-100 down for overhaul. The AM
phone parts were all gone when I got the DX-100. I am going to dpo the
mods to include the linear operation in phone mode to amplify SSB
signals and keep the class C operation for it's CW operation - ala the
Apache (TX-1). Grid block keying has already been part of this
particular DX-100.

Sometimes QRP is just not enough.

73,

Bill KU8H

On 11/10/19 7:35 AM, Don Richards wrote:
Hi Gordon
I ran across this a while back but never tried it.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://frrl.files.wordpress.com/2008/09/hotwaterforthek2.pdf&ved=2ahUKEwjwzsTQ09_lAhWsmuAKHQ1MCyYQFjACegQIARAB&usg=AOvVaw1PdjqVxSUEw-wayoqwuZyO

73 Donve3ids
--
bark less - wag more



Re: uBitx Version 4.3 calibration

zl1rd@...
 

Hi Vic

Where did you get this information from please?  There does not seem to be any other posts indicating version  4.3, which I have, is different.  My radio "works" but has very low audio levels and receiver is quite deaf especially above 80m band. I am not sure how to approach this issue.


Cheers,

Rob
zl1rd@...

Re: Nextion 5" display noise #noise #ubitx #nextion

Philip
 

Try swapping the Black, and Brown wires on the Volume control.
Black to the wiper, and Brown to the hot end. Sunil's instructions are incorrect.

Philip G7JUR

Re: ubitx raduino issue/AKA the radio doesn't receive

Gordon Gibby
 

you can use any waterfall (e.g. FLDGI, or even packet sound card software) to do the same.


On Tue, Nov 12, 2019 at 2:45 PM Evan Hand <elhandjr@...> wrote:
zl1rd,

Most likely the problem is the BFO adjustment.  We would need more information on which model and what equipment you would have for testing.

I personally have found a free Audio Spectrum Analyzer (google one on the net) was the most helpful.  You can plug in a usb mic, have it close to the speaker of the uBitx, tune to a clear frequency, and adjust the BFO for the noise plateau to be centered between 500 and 3,000 hz.  The BFO has the most impact on the receive sensitivity.

There are other methods on groups.io.  You can search for them with BFO Setting or something simalar, just remember that the v3 and v4 are at a different frequency than the v5.

Hope that helps,
Evan
AC9TU
 

Re: ubitx raduino issue/AKA the radio doesn't receive

Evan Hand
 

zl1rd,

Most likely the problem is the BFO adjustment.  We would need more information on which model and what equipment you would have for testing.

I personally have found a free Audio Spectrum Analyzer (google one on the net) was the most helpful.  You can plug in a usb mic, have it close to the speaker of the uBitx, tune to a clear frequency, and adjust the BFO for the noise plateau to be centered between 500 and 3,000 hz.  The BFO has the most impact on the receive sensitivity.

There are other methods on groups.io.  You can search for them with BFO Setting or something simalar, just remember that the v3 and v4 are at a different frequency than the v5.

Hope that helps,
Evan
AC9TU
 

Re: ubitx raduino issue/AKA the radio doesn't receive

zl1rd@...
 

Hi John

Wonder if you have solved this problem?  I just finished my uBITX and experience the same issues you have....  receiver sensitivity very low etc.  Would you mind responding to zl1rd@... and let me know about the progress you have made.  Your help is much appreciated.

Regards,


Rob
zl1rd

Re: S meter locking up

howard winwood G4GPF
 

It caught me out too, audio not good, AGC not good so decided to trace wiring. What a difference it makes!!!!

G4GPF

On Mon, 11 Nov 2019, 23:21 Philip, <philip.g7jur@...> wrote:
That clever person could been me.
I see that the latest drawing is still wrong, This error has a long history.

Philip G7JUR

Re: S meter locking up

Maurice Bersan
 

Yes, the brown wire is actually v high and black is v medium.

On 12 Nov 2019 10:15 a.m., Justin Phillips K5AXL <dolmdemon@...> wrote:
I'm confused, are you talking about the connection from the volume jack on the front panel board supplied by inkits? The brown and black wires are reversed?

Re: S meter locking up

Justin Phillips K5AXL
 

I'm confused, are you talking about the connection from the volume jack on the front panel board supplied by inkits? The brown and black wires are reversed?

Re: S meter locking up

Maurice Bersan
 

Yes, however the wire colour changed with the extra board.
Apologies for miss spelling your name on my earlier post.
Thanks again Philip.

Re: S meter locking up

Maurice Bersan
 

Well thanks Phillip, wiring it up correctly made a big difference to the ALC operation....
Cheers
Maurice

On 12 Nov 2019 7:15 a.m., Philip <philip.g7jur@...> wrote:
That clever person could been me.
I see that the latest drawing is still wrong, This error has a long history.

Philip G7JUR

Re: S meter locking up

Justin Phillips K5AXL
 

Could this be why my audio amp squeels when I turn the preset pot more than 1/16th up from off? 


On Mon, Nov 11, 2019, 5:39 PM Philip <philip.g7jur@...> wrote:
Here is my posting from last year

The wire up drawing has an error regarding the volume control connections. It shows the orange wire as being Vol_high. And the yellow wire as being Vol_mid, going to the wiper.
The orange wire is in fact the Vol_mid, and should go to the wiper. And yellow to the hot end.
The pictures are correct.

Philip G7JUR

Re: Are these output watt rating crazy?

 

Oh,

There's not much to do wrong, it's all up to the software!  But this program always seems to agree with the Elsie program by Tonne Software, so I think it's OK.  The values I am taking are from the v3 schematic -- I think the filters are still the same although arranged differently now.  I thought lots of people would have run these through a simulator program already; especially when investigating power variations it could be interesting to get some confirmation of the cutoffs and input impedances.

Cheers,


Mark.

Re: S meter locking up

Philip
 

Here is my posting from last year

The wire up drawing has an error regarding the volume control connections. It shows the orange wire as being Vol_high. And the yellow wire as being Vol_mid, going to the wiper.
The orange wire is in fact the Vol_mid, and should go to the wiper. And yellow to the hot end.
The pictures are correct.

Philip G7JUR

Re: Are these output watt rating crazy?

Jerry Gaffke
 

Mark,

That gives me confidence in how you are simulating these LPF's.
Could be that the 80m LPF really does have a corner at 7mhz.
Or could be that the boards are not being built exactly as described by the v5 schematic.

Jerry


On Mon, Nov 11, 2019 at 12:56 PM, Mark - N7EKU wrote:
It looks like a good filter for 30m and 40m.  Input impedance showed 50 ohms on 30m and 40 ohms on 40m.