Mini PA für my uBITX #ubitx
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Mark Schraven
Hi. I cant thank Ashhar Farhan and Ian (KD8CEC) enough for bringing me back into ham radio. The ubitx and Ians software are so much fun. I just completed my little PA using eBay modules ( MRF186 + LPF Board ) and a NANO connected via i2c to control it. Just wanted to share it. Regards Mark, DC3MS
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Art Boelke
Nice! On Sat, Jan 12, 2019 at 2:46 AM Mark Schraven <mark.schraven@...> wrote:
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Got more options with an eBay search...
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Bob — KK5R -------------------------------------------- On Sun, 1/13/19, Timothy Fidler <engstr@...> wrote:
Subject: Re: [BITX20] Mini PA für my uBITX #ubitx To: [email protected] Date: Sunday, January 13, 2019, 12:56 AM this vendor is top-cc* in Shanghai - never used him? - this is simply answering the question. There is probably only one mafr down in a tin shack somewhere in PRC and these legions of resellers.? He quotes it as? 90 w Module which is bollocks.? NB no LPF with this incarnation. some other vendors of the same basic? PCB have an LPF but it is the single relay for both in and out type - as per what the MX-P50 uses. |
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A consideration here is to wonder if any spurs, etc., get
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amplified with the amp. May need more LPF's to keep it within FCC specifications. Just a thought. Bob — KK5R -------------------------------------------- On Sun, 1/13/19, DC3MS <mark.schraven@...> wrote:
Subject: Re: [BITX20] Mini PA für my uBITX #ubitx To: [email protected] Date: Sunday, January 13, 2019, 2:58 AM Right, the module seems to be sold by many different sellers in asia. Dont expect to get documentation or service, they just sell it. The boards are named "XF-P100" and "XF-LPF-HF". ? I am not promoting these modules as the amp can be changed to whatever you like, i just wanted to control it via i2c using Arduino. @Timothy : I have tried to run in on 24V and my Zetagi HP500 showed? 90W output with 5W drive. Given the MRF186s specs, wheres the catch ? |
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I confused "spur" with "harmonic." I see your point, though.
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Thanks for making me, and possibly others, to think more about the real culprits. Actually, an amp is not really necessary because more is achieved by a proper antenna and more antenna work. Major problem is that many people do not turn up the gain on their receivers and once this is done, the QRP rig is usually heard. The next consideration is some other station that is nearby that runs high power and covers up the QRP signal. It's ll part of the QRP World. I remember days of the HW-7 and HW-8 and the experience gained there. QRP is more than a simple technique, though. It's pickled with patience. Bob — KK5R -------------------------------------------- On Sun, 1/13/19, Jerry Gaffke via Groups.Io <jgaffke@...> wrote:
Subject: Re: [BITX20] Mini PA für my uBITX #ubitx To: [email protected] Date: Sunday, January 13, 2019, 11:34 AM More than just a thought. Here's another:? a LPF won't cure the spurs, they can be lower in frequency? than your fundamental.? ? With the mike gain cranked up as some do to get? sufficient power out on the high bands, spurs can be 20x stronger (or worse) than even the rather lax -43dbc spec of our beloved FCC. The uBitx is marginal at best with regards to spurs and harmonics and IMD and residual carrier. Excusable on a QRP rig perhaps, but I wouldn't slap a linear on it unless I had the gear to verify that the uBitx had been modded sufficiently to have a clean signal. ? On the other hand, I guess all those FCC guys are out on leave these days .... Jerry On Sun, Jan 13, 2019 at 02:43 AM, Bob Lunsford wrote: A consideration here is to wonder if any spurs, etc., get amplified with the amp. May need more LPF's to keep it within FCC specifications. Just a thought. |
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Mark, I'm in the process of getting a BITX40 (waiting for
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shipping notification and tracking number) and those old Heathkit days are moving into hazy history and a desire to never revisit them. The only thing I have now is an HW-2036 2M for monitoring 52S mostly and a RS HTX-252. I live in a 2M depressed area. I've build nearly everything Heath had. Had an HW-104 and an SB-104 but the FT-450AT I had made them look like WW1 submarines. I even had a Drake TR7 which was to me the Cadillac of HF radios but the 450 was much better for me. All that is gone now. Moving into the HF Signals arena. These Ubitx/TITX40 radios are great. It's a new kind of technology to me with the Raduino. The UbitX is surprisingly good on reception and this means from 500KHz to 30MHz. Big question is, when will the V5 board be available? Bob — KK5R -------------------------------------------- On Mon, 1/14/19, DC3MS <mark.schraven@...> wrote:
Subject: Re: [BITX20] Mini PA für my uBITX #ubitx To: [email protected] Date: Monday, January 14, 2019, 1:23 AM Bob, i deeply respect long time hams sharing their vast knowledge with new-to-ham Operators, but i really didnt expect this discussion to start. Sure its not necessary, nor is it necessary that i recap an Heathkit SB101, SB610, SB620 and build an extra Hamdesk in the basement to set the line up together with the just acquired SB200. If i would do my antenna and CW work right, all i needed would be pixie monobanders for each band. I am not complaining about objections regarding signal quality - i think that is pretty important. |
AA9GG
Bob Lunsford