Re: RF power chain mods and improvements..
>>The bands from 18MHz - 21.450MHz at least will have the offending spur stripped out in the LPFs after the finals.?? I agree that amplifying these spurs is not ideal and adds to the problem of drive...? I speculate that this is why there may be a low in power output around these frequencies?? <<
No.? The filter in use for 18mhz is the one used for 14mhz and has a lower cutoff around 20-21mhz and
the firmware selects the 35mhz cutoff filter for 21mhz or higher.
They have no impact on low output.? Its simply the gain of the amp at 80m is around 61DB and by 10M its barely 50db
and the IRF510 are not the offenders.? If the amp were perfect the spur would be greater.
Allison
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FT8 does not have a heavy duty cycle. The other modes DO.
I have a small 5v fan with a dropping resistor to quieten it, and the long duty cycle WSPR works fine.
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Re: RF power chain mods and improvements..
The spur of interest is predictable;? ?Fspur= 45mhz - output frequency(mhz)
For? ? Spur at
29? ? ? ? 16
28? ? ? ? 17
24.9? ? ?20.1
21.45? ?23.55
None above are filterable with simple low pass filter for the band of inerest its a band pass issue.
18.1? ? ?26.9? ?(happens to be higher than the 20m to 17M low pass filter. and not as big a problem
It occurs at 45mhz minus the output frequency so for 28mhz the spur will be at about 17mhz during transmit.
Its level ican be as much as -50dbc or if the audio drive is turned up to near overdrive -25dbC
as measured before the power amp.? Since the amp is has more gain at lower frequencies?
the spur may be 3-6 db stronger.
It can only happen for the band that use the 30mhz low pass filter (20mhz and up).
All the other bands lower the inboard 9 element low pass filter at 33-35mhz stops it
and the band selected filters with cutoff lower than that (80, 60, 40 30, 20, 17M)
are better but try to not over drive.
This is true for all modified or not.? None of the mods (anyones) are the case its
generated by the base radio and is only there if running SSB.? The CW
generation scheme does not create or use the 45mhz IF.
The only fix is a before the amp bandpass filters for 15, 12 and 10M and they have to be?
fairly narrow.
I'm still looking at other ways to deal with this but its there.? I have stopped with amp
work for the moment as a flat amp helps and also makes it worse.
Allison
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I too am having trouble, mostly with the Nextion library usage.
I Googled "nextion display examples without nextion library" and am doing pretty good with just the basic commands in an Arduino program.?
Just simple commands to a serial port.
Going to walk before I run. ?
Lots of YouTubes to help too.
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Yep, I have done that with a vacuum tube Heathkit SB 102 with a wonderful outcome. ?
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I just bought a TenTec Delta 580 that has no ability to interface with a computer.? HOWEVER...it has the ability to add an external VFO.
I wonder if a Radiuno could be setup to provide an external VFO for the Delta?? Wouldn't be able to bandswitch, but should be able to tune across the dial with it, at least.
Thoughts?
--
73 de W5NNH
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Jack, that is a very nice looking display, very impressive.?
Nextion ?users I would like to know what software is the easiest to use with it I downloaded their software and find it about as user friendly as an alligator , or it is to me. I am not finding any real good documentation on the v0.53 that is current and the older docs just don't ?seem to match up.
kn4ud ?
--
Allen ?Merrell
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I found an old BUD box about 10x6x3 1/2 inches.? The uBITX fit in just fine when I cut a hole for the display and out the back for? the heat sinks.? ?I later found a large heat sink so fastened it to the back of the BUD box to cover the hole and bolted the finals to the heat sink.? I have replaced the finals to the RD16HHF1.? This with a few other mods gives a more even power out and also allows me to bolt the transistors to the heat sink without any insulation.
I mounted the AVC board to one of the relays with a dab from my hot glue gun.
Used some white on clear tape to do the labels.? I had been wanting a reason to buy one of the labeling machines as they are only around $ 25.??
?
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Re: RF power chain mods and improvements..
I meant spurs transposed from the wanted frequency
Il 03/giu/2018 09:15, "iz oos" < and2oosiz2@...> ha scritto: How much down are the spurs? Are they predictable (translated)? Even with an unmodified Ubitx?
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That makes me think of the Purdum/Zia DDS VFO I just finished making work in the 40m rig I built from their kit/instructions.
I pretty much rebuilt my dining room into a workshop just so I'd have a good bench to build that radio, BTW. Best article I ever read in QST. ;)
-- Gwen NG3P
On Sun, Jun 3, 2018 at 10:03 AM John Kemker < kemkerj3@...> wrote: I just bought a TenTec Delta 580 that has no ability to interface with a computer.? HOWEVER...it has the ability to add an external VFO.
I wonder if a Radiuno could be setup to provide an external VFO for the Delta?? Wouldn't be able to bandswitch, but should be able to tune across the dial with it, at least.
Thoughts?
--
73 de W5NNH
--
-+-+-+-+-
Jenny Everywhere's Infinite: Quark Time
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Re: boosting the power on 28 MHz
#ubitx
Thanks, Allison. I'm actually going to stay out of trouble for the moment and wait until these mods are "final"-ized (pardon the pun. You know far more what you are doing than I can understand - although I am trying. I'm just looking through my parts box to see if I have some things you are talking about, in anticipation!? :)
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Re: Can't get my uBitX to transmit CW on the Dial frequency
Ok, so this issue is of great interest to me. So far, CW is the only mode I've been working...and unsuccessfully at that. My uBITX is still using the factory installed firmware - I haven't changed over to the CEC ware yet. It seems no matter how I holler at received stations, they just do not hear me. My dial frequency shows the same freq as when in normal USB mode - it does not change. Would this be made simpler if I just went and loaded the CEC software?
Thanks,
Dave
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Ian, thanks for the quick reply. Mike N6CMY
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I just bought a TenTec Delta 580 that has no ability to interface with a computer.? HOWEVER...it has the ability to add an external VFO.
I wonder if a Radiuno could be setup to provide an external VFO for the Delta?? Wouldn't be able to bandswitch, but should be able to tune across the dial with it, at least.
Thoughts?
--
73 de W5NNH
|
Mharpen
Thanks for using CEC firmware Yes, available on stock lcd (16x02 parallel LCD). Just check the S-Meter option in uBItX Manager. I am based on uBITX which was not modified when I wrote the firmware.
If you want to use the CEC firmware without any modification, and you need a S.Meter or SDR (Pan adapter), connect the required module to uBITX and activate it in uBITX Manager.
The sensor part for S.Meter can be made in any way. CEC 1.08 supports most S.Meter sensors.
The first picture on the link below shows the S-Meter on the 16x02 LCD.
Ian KD8CEC
Question: ?will the S-meter feature in v1.08 work with the stock LCD?
Mike N6CMY
-- Best 73 KD8CEC / Ph.D ian lee kd8cec@...
(my blog)
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Re: how find wiring ssm2167 on ubitx
I used the info in this thread to wire up mine.? Works great for me!
/g/BITX20/topic/16775725#47078
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Question: ?will the S-meter feature in v1.08 work with the stock LCD?
Mike N6CMY
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On Sun, 3 Jun 2018, 17:38 Praba Karan, < vu3dxr@...> wrote: This means stock heat sink supplied is just enough for ft8?
On Sun, Jun 3, 2018, 4:30 PM Ashhar Farhan < farhanbox@...> wrote: The ft8 has an overall cycle of 50%.i use it with the standard issue heatsink. - f
I am not using the irf510 in my ubitx, but rather the irf630. My heatsink is an old pentium 4 sink cut in half with both fets bolted to it through mica insulators and thermal grease.
On FT8 the heatsink does a wonderful job and only gets luke warm, even with back to back QSOs. However, on modes like WSPR, I had to attach a small fan or the sink would become too hot to touch.
But I am also pretty hard on my ubitx with running the PA on 36 volts and 1-1.4 amps. (I consider one amp of current to be running the PA wide open since I use a bias current of 160ma)
On Sun, Jun 3, 2018, 5:44 AM Praba Karan < vu3dxr@...> wrote: What are heat sink requirements of ubitx for ft8 and other digital modes?. Just binding irf510 on back panel of casing(like in sunils case) is enough to withstand heavy duty cycle demanded by ft8?
--
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N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist
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I just wondered, as we're using the BuyDisplay.com displays which also offload the processing to the display. We're using the SPI interface with the touch screen feature as well. Are the Nextion users also using a touch screen feature? (I wasn't a touch screen fan at first, but now I really like it. Much more direct than encoder scrolling.) The JackAl display looks like:
Jack, W8TEE
On Saturday, June 2, 2018, 11:32:40 PM EDT, Mike Woods <mhwoods@...> wrote:
Jack
The nextion displays have a built in processor on the driver
card.? This is configurable with a supplied Windows client.
Essentially the nextion talks to the raduino with serial commands
sending "meta commands".? E.g. I am now on 3.512.245 MHz.??? Or in
the other direction, "LSB selected".?? In codes of course!
This provides complete independence between the display software
and the hardware control of the rig.?? People can come up with
their on UX for the display independent of a standardised protocol
being developed to interface with the CEC firmware.
Makes a whole lot of sense to me!
Mike ZL1AXG ubitx.net
On 3/06/18 2:12 PM, Jack Purdum via Groups.Io wrote:
I see a lot of post about the Nextion display. What
advantages does the if have over the mcufriend displays?
Jack, W8TEE
On Saturday, June 2, 2018, 4:30:23 PM EDT, Allen
Merrell via Groups.Io <kn4ud@...>
wrote:
I have a 3.2 ordered and waiting for it to arrive.
I am using the 1.08CEC firmware from Dr. Ian and like
it a lot. I am adding 8 switches to it. I know the
manager has options for 6 but I am adding one for FKEY
and momentary toggle for PTT. I would appreciate any
information I can get on the Nextion Display. I
downloaded the software on the Nextion site but have
not loaded it yet to check it out. Thanks Dr Ian for
all your great work.
73's kn4ud
kn4ud@...
--
Allen ?Merrell
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Re: uBITX physical comm port - newbie question
I used a 7/16 drill for the mini USB, it clears no problem, and 5/64 for the mounting screws.?
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This means stock heat sink supplied is just enough for ft8?
On Sun, Jun 3, 2018, 4:30 PM Ashhar Farhan < farhanbox@...> wrote: The ft8 has an overall cycle of 50%.i use it with the standard issue heatsink. - f
I am not using the irf510 in my ubitx, but rather the irf630. My heatsink is an old pentium 4 sink cut in half with both fets bolted to it through mica insulators and thermal grease.
On FT8 the heatsink does a wonderful job and only gets luke warm, even with back to back QSOs. However, on modes like WSPR, I had to attach a small fan or the sink would become too hot to touch.
But I am also pretty hard on my ubitx with running the PA on 36 volts and 1-1.4 amps. (I consider one amp of current to be running the PA wide open since I use a bias current of 160ma)
On Sun, Jun 3, 2018, 5:44 AM Praba Karan < vu3dxr@...> wrote: What are heat sink requirements of ubitx for ft8 and other digital modes?. Just binding irf510 on back panel of casing(like in sunils case) is enough to withstand heavy duty cycle demanded by ft8?
--
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N5WLF, Greggory (or my nickname, Ghericoan)
General Class, Digital Radio Hobbyist
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Gwen Patton
Jay - WS4JM