[Elecraft] 160 meter low transmit
W3FPR - Don Wilhelm
w3fpr at earthlink.net
Fri Aug 26 15:22:40 EDT 2005
Don,
Until we get a handle on what is really happening, set CAL CUR to 4 amps for
now. It won't really hurt anything as long as we keep the power down to
about 5 watts.
I don't have an immediate answer for why the HI CUR messages are behaving
that way, but we will check it after 160 meters is working - it may be
related, but right now it is not informative.
We can do the detail de-bugging off-reflector and then you can report the
results after it is cured.
73,
Don W3FPR
> -----Original Message-----
> From: Don Clark [mailto:kes4845 at cox.net]
> Sent: Friday, August 26, 2005 3:03 PM
> To: w3fpr at arrl.net; elecraft at mailman.qth.net
> Subject: Re: [Elecraft] 160 meter low transmit
>
>
> One additional note. An additional note. When I tune on 160m,
> then tune on
> 80m, I get a Hi Cur on 80 m. If I turn the tune off on 80 then
> retune on 80
> I get no Hi Cur. I do not get a hi Cur on 160 after tuning on 80m.
>
> Don
>
> ----- Original Message -----
> From: "Don Clark" <kes4845 at cox.net>
> To: <w3fpr at arrl.net>; <elecraft at mailman.qth.net>
> Sent: Friday, August 26, 2005 2:29 PM
> Subject: Re: [Elecraft] 160 meter low transmit
>
>
> > Don,
> >
> > I pulled C13, 14 last night and both were 1300 pf on my meter.
> >
> > I used the RF probe I contructed from the K2 Elecraft kit parts in 2000.
> >
> > Voltage
> > Component 80m 160m
> >
> > D6 40.7 mv 57.2 mv
> > D7 40.9 mv 57.8 mv
> > W6 21.6 mv 13.4 mv
> > Q5 298 mv 0
> > Q6 1.8 volts .9 volts
> >
> > Don - KA6AKH
> >
> >
> > ----- Original Message -----
> > From: "W3FPR - Don Wilhelm" <w3fpr at earthlink.net>
> > To: "Don Clark" <kes4845 at cox.net>; <elecraft at mailman.qth.net>
> > Sent: Friday, August 26, 2005 7:42 AM
> > Subject: RE: [Elecraft] 160 meter low transmit
> >
> >
> > > Don,
> > >
> > > With that information, I would suspect the bandpass filter (even if it
> > > receives 160 meters fine) - re-check C13 and C14 for the correct value
> of
> > > 1200 pf.
> > >
> > > If that does not correct things, use an RF probe or 'scope and compare
> RF
> > > Voltages between 160 meters and 80 meters with the power set
> at about 5
> > > watts. Check at the following points (you can stop at the first one
> that
> > is
> > > substantially lower on 160) - cathode of D6 or D7 first -
> then at jumper
> > > W6 - then the collector (case) of Q5 - next the collector
> (tab) of Q6 -
> > then
> > > the collector of Q7 and collector of Q8.
> > >
> > > Let us know where the 160 meter RF is being lost (RF Voltage
> > substantiallly
> > > less than that on 80 meters) and we can likely home in on the problem
> > area.
> > >
> > > 73,
> > > Don W3FPR
> > >
> > > > -----Original Message-----
> > > >
> > > > My K2 is serial 1683. I built it in 2000. With my initial kit,
> > > > I added the
> > > > SSB capability and the 160 capability; however, since I
> didn't have a
> > 160
> > > > antenna then, I didn't complete the 160 alignment. I built the
> > > > KPA100 over
> > > > the weekend and before closing up the rig, I decided to align 160.
> When
> > > > applying the 2 watts via the power dial and adjusting L3
> and L4, I can
> > get
> > > > no more than 1.3 to 1.4 watts out. I do receive 160
> signals, and well
> > at
> > > > that. I compared my K2 to my FT-1000D and the K2 signal is received
> > more
> > > > strongly. I first reheated all the solder points including those
> > > > mods that
> > > > were done to the RF board for the 160 capability and the pin
> > > > connectors, but
> > > > no increase in power. I demounted the toroids on the module,
> > > > retinned them
> > > > and put them back, but still no increase in power. I tested the
> > > > toroids for
> > > > continutity on the tinned elements before remounting them, and they
> > tested
> > > > fine.
> > > >
> > > > I measure 1.3 to 3 volts at R30 from 1800 to 2000. I connected a
> > > > dummy load
> > > > in front of the LPF and get the 1.2 watts there. Adjusting the
> > > > power knob
> > > > doesn't change the output at all. I took apart the LPF and
> > > > tested each Cap
> > > > and values are fine. L5 is the correct value. I pulled and test
> > > > C75, C13,
> > > > and C14, all ok. All the Caps in the pre-driver, driver
> and power amp
> > are
> > > > all the correct values. The only one I couldn't check is the one
> > between
> > > > the 2 power transistors on the bottom of the board.
> > > >
> > > > The resistance of my relay coils meets the specifications.
> > > >
> > > > I checked the T4 as noted in the notes on 160 issues on the Elecraft
> > > > website, and mine is to spec with the 3 windings for points 3 and
> > > > 4. My kit
> > > > didn't have the 39 pf cap for one near U5. It has a 68 pf.
> > > >
> > > > I am outputting the K2 to a dummy load during my transmit tests. My
> > power
> > > > supply is outputting 13.8 volts.
> > > >
> > > > Don - KA6AKH
> > > >
> > > --
> > > No virus found in this outgoing message.
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> > > Version: 7.0.344 / Virus Database: 267.10.15/81 - Release Date:
> 8/24/2005
> > >
> >
>
> --
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>
--
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