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Re: Wow... 15 volts in and a bunch out..

 

Jerry,

For some that is a mountain. Others maybe an afternoon.

I tried to balance it with very few new parts, no involved
measurements, maximum HF functionality with
improved filtering.

For the "but 10M" I offer with straight though using the mentioned filter
will solve the 10M issues both harmonics and spurs.?
That filter type would likely work for 12M and 15M with the
appropriate frequency filter.

Allison
Re: Intermodulation Performance

 

Allen and David,

Right now this is just a test to see what the results look like and "if there is a pony in the room". We may just provide the Gerber files, the LPF Relay boards, A complete LPF upgrade kit (not sure I can handle the potential demand after the AGC/Click activity), or just give it to someone else to run with ...?

73 Kees K5BCQ
Re: Wow... 15 volts in and a bunch out..

 

I use a 78s05 voltage regulator , at 2 amps it gives a bit more headway and runs cooler .


On Sun, 19 Aug 2018 at 4:23, RCBoatGuy via Groups.Io
<ijnfan-HamRadio@...> wrote:
From the sounds of it, this temperature measurement was taken in open air, indoors @ room temperature.? It will get considerably hotter in an enclosure, and even hotter yet if that enclosure is outside in direct sunlight on a summers day.?

I strongly recommend both the heat sink and the resistor, especially if you plan on using this outdoors.?

73,

Carl, K0MWC

Re: Wow... 15 volts in and a bunch out..

 

Jerry, Allison, etc...

From tests by Allison, Warren, Kees, and others it seems that part of the problem
may be in drivers for the IRF510s.? As these devices run out of gain at higher
frequencies they start generating garbage(?).? If that is true then part of the solution
would seem to be fixing what gets into the IRF510s before it gets there.?
Receive side has not received much attention other than recent IMD comments, but
Maybe fixing the transmit drivers is worthwhile to look at.?

The original BITX was based on fixed gain amplifiers.? This eliminated level variations
due to frequency.? Maybe we can only get a few DB from a 2Nxxxx but by fixing the gain
per device at some level that will not have it pushing up against its maximum gain-frequency
limit at any frequency where it is bing used, we could have the same drive at all frequencies.
This may require that several lower gain stages would be needed in place of one higher
gain stage, but still could provide necessary gain and clean output at all frequencies.?

We have learned a lot since the uBITX became available.? All this is probably of limited
value to the present uBITX without extensive modifications.? I have not talked with Farhan
about this but maybe there could be an upgraded uBITX version to replace the present
design and incorporate what we have learned.? Have we learned enough yet for that to be
a viable direction?

Arv
_._


On Wed, Aug 22, 2018 at 11:50 AM Jerry Gaffke via Groups.Io <jgaffke=[email protected]> wrote:
Allison,

That summary is much appreciated.
Looks like a reasonable to-do list,
anything much more than that and we may as well rebuild from scratch.

Thanks!

Jerry, KE7ER



On Wed, Aug 22, 2018 at 10:21 AM, ajparent1/KB1GMX wrote:
On Wed, Aug 22, 2018 at 08:31 AM, Jerry Gaffke wrote:
Yes, the whole thing needs a re-think.
But other than adding external LPF's (or hacking the existing relay scheme),
I'm wondering if there are any other easily performed improvements
that owners of v3 and v4 boards can do.
OK this is radical by some belief.
First give up on the idea of 20mhz and above too many tough fixes needed.
Both fixes are not fun but make sense for believable accomplishment.

NOTE:? it does nto disable 20mhz and up.? An external BANDPASS
filter could be used with 10M and would work better with this change.
see?

Power amp help:
*Replace Q90 with BFR106 or SMT 2N2369A
*C81 470 to 1000pf to keep the 80m power in balance.
*Replace all of the 3904s with 2n2222A? (predriver and driver)
Optional mod:

The IRF510s are mounted with .45" leads and is bad practice in power amps.
Its possible to shorten them to under .09"
Required materials, two insulator kits and suitable heat sink for case anticipated.
It improves power out some? at 10M.
* Remove IRF510 and remove heatsinks.
* bend leads 90 degrees up at the case.
* insert leads into board from bottom so that IRF510 case touches.
* use heatsink insulator kits and heatsink.? Heatsink must be grounded
? for better stability.

Filter help:

* remove the relays KT1 though KT3 an K3.? (replace if damaged).
* disable the use of K3 for audio switching it causes issues.
* remove all the interconnecting traces for RF paths for all.
? DO not cut the traces to the relay coils on the RF ones.
* Using COAX jumper from K3 to K1 for RX path. Ground braid
? ends of the underside ground plane.
* Reinstall relays on the underside!
* using short wires from the input side and output side of the fitlers
? to the relays NO contacts.
? KT1 is? 20/17M filter
? KT2 is? 40/30M filter
? KT3 is 80/60M filter.
?K3 is antenna transfer from jack to RX or TX fitlers.?
* jumper the NC contacts for each relay.
* daisy chain the wiper contacts from one relay to next.
* mod the code to select the right relay for band.

This is a tested set of modifications.? With it you loose 20mhz (unless you use external filter)
and up but the filter issue is FIXED for the lower bands.? If some one wants to write it up
I can help.

Allison
Re: Intermodulation Performance

Warren Allgyer
 

Hi Kees

I would be honored to test and record data, publish if you wish, any filters you would be willing to send. I would of course return them after testing is complete. If you would like to proceed please contact me privately for shipping info.?

Thank you Kees.?

WA8TOD
Re: Wow... 15 volts in and a bunch out..

 

Allison,

That summary is much appreciated.
Looks like a reasonable to-do list,
anything much more than that and we may as well rebuild from scratch.

Thanks!

Jerry, KE7ER



On Wed, Aug 22, 2018 at 10:21 AM, ajparent1/KB1GMX wrote:
On Wed, Aug 22, 2018 at 08:31 AM, Jerry Gaffke wrote:
Yes, the whole thing needs a re-think.
But other than adding external LPF's (or hacking the existing relay scheme),
I'm wondering if there are any other easily performed improvements
that owners of v3 and v4 boards can do.
OK this is radical by some belief.
First give up on the idea of 20mhz and above too many tough fixes needed.
Both fixes are not fun but make sense for believable accomplishment.

NOTE:? it does nto disable 20mhz and up.? An external BANDPASS
filter could be used with 10M and would work better with this change.
see?http://www.kitsandparts.com/W3NQN_May_June_1998_QST.pdf

Power amp help:
*Replace Q90 with BFR106 or SMT 2N2369A
*C81 470 to 1000pf to keep the 80m power in balance.
*Replace all of the 3904s with 2n2222A? (predriver and driver)
Optional mod:

The IRF510s are mounted with .45" leads and is bad practice in power amps.
Its possible to shorten them to under .09"
Required materials, two insulator kits and suitable heat sink for case anticipated.
It improves power out some? at 10M.
* Remove IRF510 and remove heatsinks.
* bend leads 90 degrees up at the case.
* insert leads into board from bottom so that IRF510 case touches.
* use heatsink insulator kits and heatsink.? Heatsink must be grounded
? for better stability.

Filter help:

* remove the relays KT1 though KT3 an K3.? (replace if damaged).
* disable the use of K3 for audio switching it causes issues.
* remove all the interconnecting traces for RF paths for all.
? DO not cut the traces to the relay coils on the RF ones.
* Using COAX jumper from K3 to K1 for RX path. Ground braid
? ends of the underside ground plane.
* Reinstall relays on the underside!
* using short wires from the input side and output side of the fitlers
? to the relays NO contacts.
? KT1 is? 20/17M filter
? KT2 is? 40/30M filter
? KT3 is 80/60M filter.
?K3 is antenna transfer from jack to RX or TX fitlers.?
* jumper the NC contacts for each relay.
* daisy chain the wiper contacts from one relay to next.
* mod the code to select the right relay for band.

This is a tested set of modifications.? With it you loose 20mhz (unless you use external filter)
and up but the filter issue is FIXED for the lower bands.? If some one wants to write it up
I can help.

Allison
Re: boosting the power on 28 MHz #ubitx

 

As a 6M radio I'd give it a, your not serious..

At a bare minimum with enough mods to meet the FCC -50dbc for spurs and trash.
* band pass before power amp.
* better output filter.
*Then dump the whole power amp as its maybe .3W at 6M or better said a lot of
?effort for little power.? (at a minimum replace all the 3904s with BFR106 and 5109s)
?The IRF510s can make good power there (assuming short leads).
*Add a RF LNA as by weak signal standards deaf as a stump.?

As a single band radio doable.

Allison
Re: Wow... 15 volts in and a bunch out..

 

Jeffery,

One last step to the last #57649..

Once the relays are rewired the code must change.

From this:
/**
?* Select the properly tx harmonic filters
?* The four harmonic filters use only three relays
?* the four LPFs cover 30-21 Mhz, 18 - 14 Mhz, 7-10 MHz and 3.5 to 5 Mhz
?* Briefly, it works like this,?
?* - When KT1 is OFF, the 'off' position routes the PA output through the 30 MHz LPF
?* - When KT1 is ON, it routes the PA output to KT2. Which is why you will see that
?*? ?the KT1 is on for the three other cases.
?* - When the KT1 is ON and KT2 is off, the off position of KT2 routes the PA output
?*? ?to 18 MHz LPF (That also works for 14 Mhz)?
?* - When KT1 is On, KT2 is On, it routes the PA output to KT3
?* - KT3, when switched on selects the 7-10 Mhz filter
?* - KT3 when switched off selects the 3.5-5 Mhz filter
?* See the circuit to understand this
?*/
?
void setTXFilters(unsigned long freq){
??
? if (freq > 21000000L){? // the default filter is with 35 MHz cut-off
? ? digitalWrite(TX_LPF_A, 0);
? ? digitalWrite(TX_LPF_B, 0);
? ? digitalWrite(TX_LPF_C, 0);
? }
? else if (freq >= 14000000L){ //thrown the KT1 relay on, the 30 MHz LPF is bypassed and the 14-18 MHz LPF is allowd to go through
? ? digitalWrite(TX_LPF_A, 1);
? ? digitalWrite(TX_LPF_B, 0);
? ? digitalWrite(TX_LPF_C, 0);
? }
? else if (freq > 7000000L){
? ? digitalWrite(TX_LPF_A, 1);
? ? digitalWrite(TX_LPF_B, 1);
? ? digitalWrite(TX_LPF_C, 0);? ??
? }
? else {
? ? digitalWrite(TX_LPF_A, 1);
? ? digitalWrite(TX_LPF_B, 1);
? ? digitalWrite(TX_LPF_C, 1);? ??
? }
}

To this:
/**
?* Select the properly tx harmonic filters
?* The three harmonic filters use only three relays
?* the three LPFs cover? 18 - 14 Mhz, 7-10 MHz and 3.5 to 5 Mhz
?* if none are selected the path is straight through and use of external bandpass filter required.
?*?See the circuit to understand this
?*/
?
void setTXFilters(unsigned long freq){
? if (freq > 20000000L){? ? ? ? ? //? ?for 20 mhz and up its straight through no filters.
? ? digitalWrite(TX_LPF_A, 0);
? ? digitalWrite(TX_LPF_B, 0);
? ? digitalWrite(TX_LPF_C, 0);
? }
? else if (freq >= 14000000L){? // KT1 is picked and the 14-18 MHz LPF is selected
? ? digitalWrite(TX_LPF_A, 1);
? ? digitalWrite(TX_LPF_B, 0);
? ? digitalWrite(TX_LPF_C, 0);
? }
? else if (freq > 7000000L){ // KT2 is picked and the 14-18 MHz LPF is selected
? ? digitalWrite(TX_LPF_A, 0);
? ? digitalWrite(TX_LPF_B, 1);
? ? digitalWrite(TX_LPF_C, 0);? ??
? }
? else {? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? // KT3 is picked and the 14-18 MHz LPF is selected
? ? digitalWrite(TX_LPF_A, 0);
? ? digitalWrite(TX_LPF_B, 0);
? ? digitalWrite(TX_LPF_C, 1);? ??
? }
}
?
?
Re: Wow... 15 volts in and a bunch out..

 

On Wed, Aug 22, 2018 at 08:31 AM, Jerry Gaffke wrote:
Yes, the whole thing needs a re-think.
But other than adding external LPF's (or hacking the existing relay scheme),
I'm wondering if there are any other easily performed improvements
that owners of v3 and v4 boards can do.
OK this is radical by some belief.
First give up on the idea of 20mhz and above too many tough fixes needed.
Both fixes are not fun but make sense for believable accomplishment.

NOTE:? it does nto disable 20mhz and up.? An external BANDPASS
filter could be used with 10M and would work better with this change.
see?http://www.kitsandparts.com/W3NQN_May_June_1998_QST.pdf

Power amp help:
*Replace Q90 with BFR106 or SMT 2N2369A
*C81 470 to 1000pf to keep the 80m power in balance.
*Replace all of the 3904s with 2n2222A? (predriver and driver)
Optional mod:

The IRF510s are mounted with .45" leads and is bad practice in power amps.
Its possible to shorten them to under .09"
Required materials, two insulator kits and suitable heat sink for case anticipated.
It improves power out some? at 10M.
* Remove IRF510 and remove heatsinks.
* bend leads 90 degrees up at the case.
* insert leads into board from bottom so that IRF510 case touches.
* use heatsink insulator kits and heatsink.? Heatsink must be grounded
? for better stability.

Filter help:

* remove the relays KT1 though KT3 an K3.? (replace if damaged).
* disable the use of K3 for audio switching it causes issues.
* remove all the interconnecting traces for RF paths for all.
? DO not cut the traces to the relay coils on the RF ones.
* Using COAX jumper from K3 to K1 for RX path. Ground braid
? ends of the underside ground plane.
* Reinstall relays on the underside!
* using short wires from the input side and output side of the fitlers
? to the relays NO contacts.
? KT1 is? 20/17M filter
? KT2 is? 40/30M filter
? KT3 is 80/60M filter.
?K3 is antenna transfer from jack to RX or TX fitlers.?
* jumper the NC contacts for each relay.
* daisy chain the wiper contacts from one relay to next.
* mod the code to select the right relay for band.

This is a tested set of modifications.? With it you loose 20mhz (unless you use external filter)
and up but the filter issue is FIXED for the lower bands.? If some one wants to write it up
I can help.

Allison
Re: QRP SWR meter recommendation? #ubitx

 

A little off-topic, but looking at disassembly is important for the big processors too if you want to squeeze out the best performance. In particular, vectorizing compilers can be pretty finicky (easily derailed).? For DSP filter implementations properly vectorizing inner loops makes a huge difference.

73 Mike KK7ER
Re: Wow... 15 volts in and a bunch out..

 

Jerry,

Did you reduce the gain on the amp's driver and pre-driver stages when
adding the MMIC stage?

Yes.? I cranked them down to 11db range as the goal was about 60db total
using 2n2222a and BFR106.? The plan was assume 11db for the irf510s
(force it with feedback) and all the prior stages at 10db.? So the added 10db
of a mav11 was tolerable in the overall scheme.? I tried before q90 and after
at the drive pot.? However the systemic ground loops became obvious. Cutting
the?line form the amp out put to the filter area and driving the load from there
helped greatly.? Never was satisfied at any time with the stability.? The only
reason that kept me from frying finals was variable current limit power supply
set at 2.5A.? If I didn't have that many devices would be destroyed.

Allison
Re: Nextion 3.2 for CEC 1.097 #ubitx

MD
 

How about one for the 3.5 :^)

--
N5KBP
Re: Intermodulation Performance

 

¿ªÔÆÌåÓý

Mr. Kees, I am interested if you make this up as a consumer product like your AGC board. ?Please let me know when you get the kit and pricing figures out. ?Will you provide the ferrite cores? ?I can do the winding.

Thanks, Al
KB4RA


On Aug 22, 2018, at 11:23 AM, Kees T <windy10605@...> wrote:

Hello Warren Allgyer,

I want to thank you for all the effort you have put into the uBITX spur/harmonic problem definition and the excellent data presented. I realize your project is shelved ....but, would you be interested in trying out an 8 relay switched LPF board with 4 plug in LPFs using the parts off the uBITX board. You ran an experiment like that earlier with a perf. board. I have boards (75mm x 62mm) coming in soon and can supply the relays and misc parts (no charge).

73 Kees K5BCQ
<PCB_LPFx4_.pdf>
<PCB_LPFx4_Individual_.pdf>
Re: Wow... 15 volts in and a bunch out..

 

Allison,

Did you reduce the gain on the amp's driver and pre-driver stages when
adding the MMIC stage?

The power amp stages are serpentined in there pretty tight, I can believe more gain
at RV1 will couple into Q92,93,96,97 so as to create an oscllator.?

Yes, the whole thing needs a re-think.
But other than adding external LPF's (or hacking the existing relay scheme),
I'm wondering if there are any other easily performed improvements
that owners of v3 and v4 boards can do.

Jerry



On Wed, Aug 22, 2018 at 07:35 AM, ajparent1/KB1GMX wrote:
As to adding the 10db mimic I tried that... helps but the amp it self became
more unstable.? ?
Re: Intermodulation Performance

 

¿ªÔÆÌåÓý

Kees K5BCQ:

?

You and your teammates appear to be making progress on a uBitx RF spur and harmonic solution. Two questions: 1) Do you hope to have a solution by any defined deadline; and 2, will this solution be sold to uBitx owners through HF Signals or through a third party?

?

David A Posthuma, WD8PUO

?

From: [email protected] <[email protected]> On Behalf Of Kees T
Sent: Wednesday, August 22, 2018 11:24 AM
To: [email protected]
Subject: Re: [BITX20] Intermodulation Performance

?

Hello Warren Allgyer,

I want to thank you for all the effort you have put into the uBITX spur/harmonic problem definition and the excellent data presented. I realize your project is shelved ....but, would you be interested in trying out an 8 relay switched LPF board with 4 plug in LPFs using the parts off the uBITX board. You ran an experiment like that earlier with a perf. board. I have boards (75mm x 62mm) coming in soon and can supply the relays and misc parts (no charge).

73 Kees K5BCQ

Re: Intermodulation Performance

 

Hello Warren Allgyer,

I want to thank you for all the effort you have put into the uBITX spur/harmonic problem definition and the excellent data presented. I realize your project is shelved ....but, would you be interested in trying out an 8 relay switched LPF board with 4 plug in LPFs using the parts off the uBITX board. You ran an experiment like that earlier with a perf. board. I have boards (75mm x 62mm) coming in soon and can supply the relays and misc parts (no charge).

73 Kees K5BCQ

PCB_LPFx4_.pdf
PCB_LPFx4_.pdf
PCB_LPFx4_Individual_.pdf
PCB_LPFx4_Individual_.pdf

Re: Wow... 15 volts in and a bunch out..

 

Jerry,

The LT1252 is a decent part the best place to see it as a linear preamp?
is Elecraft K2.??

The RD16 vs IRF510 is a religious argument.? While the RD16HHF1 is good
part it had very little data or much else to prove it on paper.? The IRF510
is a capable part that has the same problem.? However there are a few designs
that have proved the IRF510 can perform well as in linear, more power, and
near equal gain.? ? I have three designs now in my hands that support that.

As to adding the 10db mimic I tried that... helps but the amp it self became
more unstable.? ? It was easier to replace the rather tepid 3904s with better.
But then you get enough gain to see the other issues.

The real solution.? Start with a new clean sheet layout.? The layout issues
are the greatest poison.

Allison
Re: boosting the power on 28 MHz #ubitx

 

Bob Heil.... Pppffff


On Thu, 31 May 2018 at 23:03, KENT HUFFORD
<khufford@...> wrote:

Like Bob Heil said. If everybody TRANSMITTED on 10m, then you may hear someone. <sic>.

?

Kent

?

From: [email protected] <[email protected]> On Behalf Of atouk
Sent: Thursday, May 31, 2018 6:01 PM
To: [email protected]
Subject: Re: [BITX20] boosting the power on 28 MHz #ubitx

?

?

On 5/31/2018 4:53 PM, Richard Spohn wrote:

It's all due to marketing!? 10 meters is called the "Magic Band".? And
everybody loves magic. - Rich WB2GXM
 ?
On 5/30/18, Bo Barry <bobarr@...> wrote:
I'm constantly surprised at the interest in 10 meters. I always check 15. If
its dead I go to 20. If it has anything on it I check 10 and hear nothing
here in NC with a simple EFHW..
 ?
But 10 was a blast back in 1954!!? ?:)
 ?
73, Bo W4GHV since '54
 ?
 ?
 ?
 ?

?
Re: boosting the power on 28 MHz #ubitx

 

¿ªÔÆÌåÓý

Huh.? That funny.? My uBITx works just fine on 6 meters.? With the proper modifications of course.

?

?

From: [email protected] [mailto:[email protected]] On Behalf Of ajparent1/KB1GMX
Sent: Wednesday, August 22, 2018 9:18 AM
To: [email protected]
Subject: Re: [BITX20] boosting the power on 28 MHz #ubitx

?

6M for ubitx is a no.??
The amp has no capability there due to drivers and predrivers.? 2n3904 is dead there.
Also the only filtering for TX path is the 33mhz low pass fitler.

The point was IRF510 is equally capable to RD16 and cheaper for those that like to fry them.

Allison


Virus-free.

--

¡­_. _._
Re: boosting the power on 28 MHz #ubitx

 

For the 17mhz spur from 28mhz ops its there we can argue how much but its there.
Since there is no filtering at all not only will it be there but a better amp or fixes
only make it worse.

FYI the few that had passable numbers for that also had little to no power out on
10 (under 2W).? Fix that and the spur improves the same amount, turn up the
mic gain it gets worse.? Add a filter so it works on 10M only it has a chance.

US Tech class license are allowed 10M phone but spurs outside ham bands are
not helpful to them.? Its why this is an attractive radio and why they can't use it.

Allison
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