Re: QCX tuning rate adjust
oops, I just ordered mica caps, and included C30, since it's also band-specific. Think I should leave it as is, or add that one, since I'll have it?
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Aaron, I had a similar problem. R27,R24&R17 interact with each other. It took a few tries but with a lot of turning on the resistors I found a sweet spot with a pronounced dip on each. It took awhile and now the receiver works great. Now to tackle the low power issue.
73, Gary. Old ham licensed since 1954.
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-----Original Message-----
From: James Daldry W4JED <jim@...>
To: QRPLabs < [email protected]>
Sent: Mon, Apr 29, 2019 3:38 pm
Subject: Re: [QRPLabs] QCX Phase Lo Min at Full CCW #qcx #alignment #problem
Hi, Aaron
R24 "adjusts the value of " R21. Since you are running out of
range at the "open" end of R24, R21 isn't big enough. You can
probably reach null by replacing R21 with an 8.2k, or if you are
not worried about the adjustment getting too fast, a 10k.
If you are not really experienced with rework on plated-thru
circuit boards, you might want to cut R21 off tight to the
resistor body to leave a pair of wire stubs, then make eyelets in
the wires of the new resistor, drop the eyelets over the wire
stubs, then solder on top of the board. Back in the '70's and
'80's RCA used to recommend crushing the part with a pair of
pliers and soldering the new part to the wire stubs.
73
Jim W4JED
I just built my QCX and everything seems great! Boot with no issue
and it linked and synced with my GPS unit.
However, when adjusting for Phase-Lo on R24, I get the minimum at
the full counter clockwise (left) rotation. Turning clockwise
results in a higher reading, and a louder tone when tested with
(out of my ears) earbuds. I feel that if I could somehow move the
resistance further then I would find a true minimum, but I'm not
sure how to go about that. Or is this okay where it is?
Visual inspection of the joints shows what I think are all pretty
good joints, and I continuity tested all the toroids from solder
to solder, so I'm fairly certain that those are at least not open
circuits.
Any help would be greatly appreciated!
Aaron
KG5TNI
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Re: QCX tuning rate adjust
Lloyd
Try squeezing turns on the LPF toroids in and out. Possibly it will get you up to 3 watts on a 13.8 volt supply. Note this rig has 2 bs170, versus 3 in those rigs from kd1jv. Not sure why Hans advertised 5w rig, except it will do that with 16 volt supply. Its a grand rig at 2.5 or 3 watts. Glad its working. Wasn't that image reject nulling the coolest thing? You should not hear any image at all until maybe w3lpl is running his kW. Enjoy!
Curt
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Re: QCX tuning rate adjust
I changed only C25/C26. I suspect that it's probably good to get
C27/C28 as well.
mike/w1mt
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On Mon, Apr 29, 2019 at 5:59 PM Lloyd K3ESE <llachow@...> wrote:
would those caps be C25-28, or C25-30?
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Re: QCX tuning rate adjust
would those caps be C25-28, or C25-30?
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Hi Mikael,
It went right over me early in the morning and I didn't hear it as it drifted further eastward.? It's going really fast!? Did I neglect to adjust my VFO to compensate for doppler shift?? Now I see only SDRNXZ (probably Jim) is receiving reports after it went silent over Moose Jaw.? Why is it not detected by others?? Out of band?? TX time off the top of the minute by more than a few seconds?
Thanks for the details about power strategy.? Yes, turning off GPS most of the time should save a lot!
Cheers
Halden VE7UTS ( at rac dot ca)
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Re: QCX tuning rate adjust
Searching the archives here will provide lots of insight.
Some have changed the caps in the LPF to better caps. I used silver
mica. Use the same values.
Others have changed the number of turns on the toroids in the LPF.
Still others have done both.
I got to 2.5 watts out on 20m by just changing the caps to silver
mica's. If I recall though my original power was close to 2w.
I would say that if you can get to 2-2.5 watts you've done good.
mike/w1mt
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On Mon, Apr 29, 2019 at 5:31 PM Lloyd K3ESE <llachow@...> wrote:
Well, I was using my WM-2 wattmeter, but reading it wrong. Actual power out send to be 1.64W.
What, if anything, can I try to increase that?
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Hi, Aaron
R24 "adjusts the value of " R21. Since you are running out of
range at the "open" end of R24, R21 isn't big enough. You can
probably reach null by replacing R21 with an 8.2k, or if you are
not worried about the adjustment getting too fast, a 10k.
If you are not really experienced with rework on plated-thru
circuit boards, you might want to cut R21 off tight to the
resistor body to leave a pair of wire stubs, then make eyelets in
the wires of the new resistor, drop the eyelets over the wire
stubs, then solder on top of the board. Back in the '70's and
'80's RCA used to recommend crushing the part with a pair of
pliers and soldering the new part to the wire stubs.
73
Jim W4JED
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I just built my QCX and everything seems great! Boot with no issue
and it linked and synced with my GPS unit.
However, when adjusting for Phase-Lo on R24, I get the minimum at
the full counter clockwise (left) rotation. Turning clockwise
results in a higher reading, and a louder tone when tested with
(out of my ears) earbuds. I feel that if I could somehow move the
resistance further then I would find a true minimum, but I'm not
sure how to go about that. Or is this okay where it is?
Visual inspection of the joints shows what I think are all pretty
good joints, and I continuity tested all the toroids from solder
to solder, so I'm fairly certain that those are at least not open
circuits.
Any help would be greatly appreciated!
Aaron
KG5TNI
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Re: QCX tuning rate adjust
Well, I was using my WM-2 wattmeter, but reading it wrong. Actual power out send to be 1.64W.
What, if anything, can I try to increase that?
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Ah well, we tried, Chris. It'll happen someday, Ill bet.
I've made more QSOs on 30m than on any other band, using the stock QCX-17 at 4 watts to the downspout.
CUL & 72 / 73,
Bill, N4QA
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So after the 1900z session on 30m? - regret no copy from you Bill N4QA but thanks anyway.? However, better than this afternoon, the session produced 4 QSOs, 3 Italian stations and 1 Spanish special event call.? Of these, one was QRP to QRP, but not a QCX at the other end.? Good fun.? Hope everyone else enjoyed it also.
Chris G4CWS
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1300Z worked N0BPA (Tony in MO), AJ8S (Jim in OH), and N2JDQ (Steve in NY) with EF wire at 24 ft. 1900Z worked N2JDQ (Steve in NY), N0BPA (Tony in MO), AJ8S (Jim in OH), W0ITT (Gary in MO), and NJ8D (Tom in MI) with EF wire at 24 ft. All on 40m where conditions were bad with lots of QSB. Tonight at 0300Z I plan to be on 80m with dipole. QCX isn¡¯t as frantic as weekly CWT but much more challenging (and gratifying) QRP to QRP. In CWT a QRP station can sneak between the cracks of a KW pileup and on a good day log 50 Q¡¯s in an hour. In an hour of QCX I probably spent 45 minutes listening to pull the sigs out of the noise and only 15 minutes operating to log 5 Q¡¯s. ? Does anyone know how to get QCX added as a club to CW Club RBN Spotter ()?? It would really be nice to spot QCX users, knowing immediately that they are QRP.? This would obviously that someone, somehow provided a list of QCX operators. ? Ken ke4rg
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Had only 20 minutes to play. One QSO with K7TD. Heard WB5BKL very weakly but could not work. I also worked N1ZF but he was not operating the QCX Party (SOTA?).
No QCX rig here but maybe some day. Running an ICOM IC-7300 at 3 watts. I was spotted on RBN with good a signal at W1NT (NH) and W7HR (WA), among others, so the 3 watts to a 132-foot end-fed long wire was getting out.
I'll try to be back on 40 at 0300.
73,
Jack, K0JP
Karlstad, MN
EN18rn
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40m, 2 qso's...both QCX OPS. It's too damn cold out to sit in 40F weather, and CQ for an hour with just 2 callers. I won't be on the late session...will simply be too cold to handle.?
KE4RG & AJ8S, thanks for the qso's.
Steve Raas?
N2JDQ?
FN13DD?
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Re: QCX tuning rate adjust
The tune rate in the menu (3.4) is the startup tune rate. If you just
want to dynamically change the tune rate, push the encoder. The second
to last page in the document is a quick cheat sheet.
Also, how are you measuring power out? I'd be very surprised if you
are really getting 7 watts out....especially on 20M.
mike/w1mt
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On Mon, Apr 29, 2019 at 3:42 PM Lloyd K3ESE <llachow@...> wrote:
When I power up the rig, I am able to enter the menu and change the tuning rate. After that, if I want to change the rate again, I must power-cycle the rig. I am able to enter the menu and change the setting, but it only affects the tuning rate the first time after power-up. Any suggestions to correct this?
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Re: QCX tuning rate adjust
oops. I just figured out how to adjust the tuning rate.
never mind!
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When I power up the rig, I am able to enter the menu and change the tuning rate. After that, if I want to change the rate again, I must power-cycle the rig. I am able to enter the menu and change the setting, but it only affects the tuning rate the first time after power-up. Any suggestions to correct this?
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I have actually successfully created this rig. Very happy OM here. No QSOs yet, but RBN says it's working.
Question: with a 13.8V supply, my wattmeter seems to show initially 7W out, which jumps to over 10W with key-down over a second or so. This couldn't be, right...?
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Hi No many Europe 40m QCX at 13:00z RBN report was good (see the jpeg) Nice to work Rich in Bexhill G0ILN with good sigs (QSB) Worked only one QCX and 2 another stations ... not many points ! Look at 19:00z I¡¯ll go again on 40m One month to finish my 30m QCX and improve my 20m QCX a bit light power ...
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Le 29 avr. 2019 ¨¤ 18:00, R.Putnam via Groups.Io < kairos1@...> a ¨¦crit?: I managed three qso at 1300 only one was qcx X? qcx? F5JKK Eric. 40m
Richard G0ILN.?
PS I should be on again? for the evening session.
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Hopefully my QSX will look just as good? ;-)
--
John AE5X
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Lloyd K3ESE
James Daldry W4JED
Ken Talbott