DUVIDAS PARA SUBSTITUIR IRF510 POR RD16HHF1 - uBITX v4
Request for help replacing IRF510 by RD16HHF1 on uBITX v4, what changes should I make? a) RD16HHF1 resting currents? b) T11 how do I do it? c) D-G feedback? d) Capacitance between the RD16HHF1 Drains? -- Sauda??es fraternais, 73/51 PY2PVB
Rubens Kamimura Tel. (18) 3746-8680 ramal 116 Cel. (18) 9-9819-2225 WhatsApp ou (18) 9-9819-2255?
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Good morning Andy and all: I have had some luck using large steel cookie and or cupcake sheets under a good Mag Mount, preferably lying on the ground but with some luck on a dining room table with visual access to the direction in which I wanted to transmit.?
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On Apr 3, 2020, at 07:26, Andy_501 <andrew.webb.501.ve4per@...> wrote:
?
I haven't read all msgs in this thread closely but if you live in
an apartment with a balcony with a metal railing you might
consider a mag? mount centered on the railing and connect the
railing electrically to the coax feedline braid.
I had a modified CB magmount that was resonant in 15 M band that
was mounted to metal railing that way and was able to get many
reliable qso's between Canada prairies and Central and South
America. Anything to the North for me was a bit attenuated by all
the steel and concrete but to the South it was wide open
unhindered radiation area.
On 2020-04-03 6:20 a.m., Bob Fischer,
Fischer Technical Services wrote:
For your "sheet of metal" to be large enough to be
effective, it would most likely be objectionable, too.
I second the recommendation someone else gave you.
Try using 1, 2, or 3 ground radial wires with the
hamstick.??? As many as possible, in different directions, as
horizontal as possible.? ?
Use as small diameter wire as you can get and run them
wherever you can hide them.
Good luck.
Bob
WB8BEL
From:
"Christopher Miller" <djmalak2k6@...>
To: [email protected]
Sent: Friday, April 3, 2020 6:44:55 AM
Subject: Re: [BITX20] Hamstick Mag Mount
I know I have said this before but I will
again now without malice.
The manager of the property is behind me
working to build out a working Hf/vhf/uhf station. They let
me put a hole in the wall to pass coax through.
The owner doesn¡¯t want exposed antennas as the
normal idiot landlord would.
I got flack for putting my dipole up with
cable tv coax.
I would want to get ham sticks and mount them
on a base. I¡¯m guessing a large sheet of metal will work
instead of the car.
Chris
For
portable use I have used a clamp-on mount (also sold to
make a hamstick dipole) attached to a metal stake.
Sticking that into the ground made a usable antenna. In
cases where I didn't think I had a good gound I attached
some radials made with split zip cord and just laid them
on top of the ground, or if in an upper story of a motel
I would clamp to a balcony railing and droop the radials
over the edge or spead around on the floor. I made
contacts with this setup, but it was a bit cumbersome to
carry along, so lately I have been using a relatively
inexpensive QRP loop and it actually works a little
better, plus it disassembles into a small easily carried
package.
I still use the hamsticks with a mag mount when going
mobile in my wife's SUV
=Vic=
|
Re: Nominal power supply voltage
On the v3 I have found a slight but noticeable decrease in the sound quality when I have increased the voltage to the receiver. I suspect that the op amp is being overdriven. The easiest way to limit the voltage to the receiver was to forward bias a diode or two in series with the power input connector.? The finals can handle much higher voltage.? You don't need to touch directly on the board.??
Touch the 2822 chip after the radio has been picking up strong signals for a while. If it is warm consider making a change in the input voltage to the receiver.
Unless you know exactly what you want to do don't go modifying anything on the board. Nearly every uBITX that I have repaired had some modification done by an owner who really did not grasp what they were doing. Repair mostly involves undoing what they "improved", including repairing traces.
73
Dave
|
I haven't read all msgs in this thread closely but if you live in
an apartment with a balcony with a metal railing you might
consider a mag? mount centered on the railing and connect the
railing electrically to the coax feedline braid.
I had a modified CB magmount that was resonant in 15 M band that
was mounted to metal railing that way and was able to get many
reliable qso's between Canada prairies and Central and South
America. Anything to the North for me was a bit attenuated by all
the steel and concrete but to the South it was wide open
unhindered radiation area.
On 2020-04-03 6:20 a.m., Bob Fischer,
Fischer Technical Services wrote:
toggle quoted message
Show quoted text
For your "sheet of metal" to be large enough to be
effective, it would most likely be objectionable, too.
I second the recommendation someone else gave you.
Try using 1, 2, or 3 ground radial wires with the
hamstick.??? As many as possible, in different directions, as
horizontal as possible.? ?
Use as small diameter wire as you can get and run them
wherever you can hide them.
Good luck.
Bob
WB8BEL
From:
"Christopher Miller" <djmalak2k6@...>
To: [email protected]
Sent: Friday, April 3, 2020 6:44:55 AM
Subject: Re: [BITX20] Hamstick Mag Mount
I know I have said this before but I will
again now without malice.
The manager of the property is behind me
working to build out a working Hf/vhf/uhf station. They let
me put a hole in the wall to pass coax through.
The owner doesn¡¯t want exposed antennas as the
normal idiot landlord would.
I got flack for putting my dipole up with
cable tv coax.
I would want to get ham sticks and mount them
on a base. I¡¯m guessing a large sheet of metal will work
instead of the car.
Chris
For
portable use I have used a clamp-on mount (also sold to
make a hamstick dipole) attached to a metal stake.
Sticking that into the ground made a usable antenna. In
cases where I didn't think I had a good gound I attached
some radials made with split zip cord and just laid them
on top of the ground, or if in an upper story of a motel
I would clamp to a balcony railing and droop the radials
over the edge or spead around on the floor. I made
contacts with this setup, but it was a bit cumbersome to
carry along, so lately I have been using a relatively
inexpensive QRP loop and it actually works a little
better, plus it disassembles into a small easily carried
package.
I still use the hamsticks with a mag mount when going
mobile in my wife's SUV
=Vic=
|
For your "sheet of metal" to be large enough to be effective, it would most likely be objectionable, too. I second the recommendation someone else gave you. Try using 1, 2, or 3 ground radial wires with the hamstick.??? As many as possible, in different directions, as horizontal as possible.? ? Use as small diameter wire as you can get and run them wherever you can hide them. Good luck. Bob WB8BEL
From: "Christopher Miller" <djmalak2k6@...> To: [email protected]Sent: Friday, April 3, 2020 6:44:55 AM Subject: Re: [BITX20] Hamstick Mag Mount
I know I have said this before but I will again now without malice.
The manager of the property is behind me working to build out a working Hf/vhf/uhf station. They let me put a hole in the wall to pass coax through.
The owner doesn¡¯t want exposed antennas as the normal idiot landlord would.
I got flack for putting my dipole up with cable tv coax.
I would want to get ham sticks and mount them on a base. I¡¯m guessing a large sheet of metal will work instead of the car.
Chris For portable use I have used a clamp-on mount (also sold to make a hamstick dipole) attached to a metal stake. Sticking that into the ground made a usable antenna. In cases where I didn't think I had a good gound I attached some radials made with split zip cord and just laid them on top of the ground, or if in an upper story of a motel I would clamp to a balcony railing and droop the radials over the edge or spead around on the floor. I made contacts with this setup, but it was a bit cumbersome to carry along, so lately I have been using a relatively inexpensive QRP loop and it actually works a little better, plus it disassembles into a small easily carried package.
I still use the hamsticks with a mag mount when going mobile in my wife's SUV
=Vic=
|
I know I have said this before but I will again now without malice.
The manager of the property is behind me working to build out a working Hf/vhf/uhf station. They let me put a hole in the wall to pass coax through.
The owner doesn¡¯t want exposed antennas as the normal idiot landlord would.
I got flack for putting my dipole up with cable tv coax.
I would want to get ham sticks and mount them on a base. I¡¯m guessing a large sheet of metal will work instead of the car.
Chris
For portable use I have used a clamp-on mount (also sold to make a hamstick dipole) attached to a metal stake. Sticking that into the ground made a usable antenna. In cases where I didn't think I had a good gound I attached some radials made with split zip cord and just laid them on top of the ground, or if in an upper story of a motel I would clamp to a balcony railing and droop the radials over the edge or spead around on the floor. I made contacts with this setup, but it was a bit cumbersome to carry along, so lately I have been using a relatively inexpensive QRP loop and it actually works a little better, plus it disassembles into a small easily carried package.
I still use the hamsticks with a mag mount when going mobile in my wife's SUV
=Vic=
|
Re: uBitx v.4 build information
My V4 shows a 470pf at C81, and my comment was a reflection of a bad pencil note on my "to do" list. Previous posts had suggested 0.01uf across C81 as improving the low power on 40m, so that's what I should have said. However, I won't be doing anything until I scope it out a bit more. The CW output is pretty low, 3w, while SSB is around 7w. Other bands below 17m are double that. But, as I said, I'll do some more testing to be sure of the scope of the issue which I see others are dealing with, as well. Thanks for the comments.
=Vic=
|
For portable use I have used a clamp-on mount (also sold to make a hamstick dipole) attached to a metal stake. Sticking that into the ground made a usable antenna. In cases where I didn't think I had a good gound I attached some radials made with split zip cord and just laid them on top of the ground, or if in an upper story of a motel I would clamp to a balcony railing and droop the radials over the edge or spead around on the floor. I made contacts with this setup, but it was a bit cumbersome to carry along, so lately I have been using a relatively inexpensive QRP loop and it actually works a little better, plus it disassembles into a small easily carried package.
I still use the hamsticks with a mag mount when going mobile in my wife's SUV
=Vic=
|
Hello,
I¡¯m curious what I would need to do to use a mobile mag mount for an HF whip without mounting it to a car. I¡¯m guessing I need to get a large sheet of metal to act as a ground plain. (Because of the lack of a car.)
Chris
|
Re: Nominal power supply voltage
I was lucky enough to be given a complete transceiver I don¡¯t want to mess with cutting traces and modifying it until I have everything set up. I just wanted to make sure I didn¡¯t need to increase the voltage.
Chris
I use 12 volts but a higher voltage can be delivered to just the PA feed to boost the rf output.
Hello,
I am currently feeding 12 volts in to my v3 uBitx. I was wondering if I should be using 13.8 volts. Will that blow up the 5 volt regulator?
Thanks,
Chris KF4FTR
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Re: Nominal power supply voltage
In the v3 the audio output chip is at its limit with 12 volts,the PA can be run from say 15. or a bit more for increased rf output
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Sorry. I sm withdrawing my statement.? V3, the TDA2822 WILL LIKELY GET DAMAGED AT HIGHER VOLTAGE.?
LIMIT TO 12.?
After all you can reduce 13.8 to 12 by some pot on the psu.?
On Fri, 3 Apr 2020, 1:05 pm Mvs Sarma, < mvssarma@...> wrote:
You can use? q3.8. Pl dont again say + /-
All the best.?
On Fri, 3 Apr 2020, 12:56 pm Christopher Miller, < djmalak2k6@...> wrote:
Hello,
I am currently feeding 12 volts in to my v3 uBitx. I was wondering if I should be using 13.8 volts. Will that blow up the 5 volt regulator?
Thanks,
Chris KF4FTR
|
Re: Nominal power supply voltage
Sorry. I sm withdrawing my statement.? V3, the TDA2822 WILL LIKELY GET DAMAGED AT HIGHER VOLTAGE.? LIMIT TO 12.?
After all you can reduce 13.8 to 12 by some pot on the psu.?
On Fri, 3 Apr 2020, 1:05 pm Mvs Sarma, < mvssarma@...> wrote: You can use? q3.8. Pl dont again say + /- All the best.?
On Fri, 3 Apr 2020, 12:56 pm Christopher Miller, < djmalak2k6@...> wrote: Hello,
I am currently feeding 12 volts in to my v3 uBitx. I was wondering if I should be using 13.8 volts. Will that blow up the 5 volt regulator?
Thanks, Chris KF4FTR
|
Re: Nominal power supply voltage
I use 12 volts but a higher voltage can be delivered to just the PA feed to boost the rf output.
toggle quoted message
Show quoted text
Hello,
I am currently feeding 12 volts in to my v3 uBitx. I was wondering if I should be using 13.8 volts. Will that blow up the 5 volt regulator?
Thanks,
Chris KF4FTR
|
Re: Nominal power supply voltage
You can use? q3.8. Pl dont again say + /- All the best.?
On Fri, 3 Apr 2020, 12:56 pm Christopher Miller, < djmalak2k6@...> wrote: Hello,
I am currently feeding 12 volts in to my v3 uBitx. I was wondering if I should be using 13.8 volts. Will that blow up the 5 volt regulator?
Thanks, Chris KF4FTR
|
Nominal power supply voltage
Hello,
I am currently feeding 12 volts in to my v3 uBitx. I was wondering if I should be using 13.8 volts. Will that blow up the 5 volt regulator?
Thanks, Chris KF4FTR
|
Re: #v6 need a 12v connectiion
#v6
One amp is not enough, you need a 3 amp supply to give a little head room.
Once you get your antenna figured out, you will want a bigger power supply. The sag would be significant. As would be the electric noise.
--
73
Dave
|
Re: #v6 need a 12v connectiion
#v6
Once you get your antenna figured out, you will want a bigger power supply. The sag would be significant. As would be the electric noise.
--
73
Dave
|
Re: uBitx v.4 build information
Curt,
I wasn't arguing against your advice.? I merely stated what Allison said worked well for her.? She made other modifications too, but the order is not always clear in the older posts.? In any case, since users' rigs all seem to be a bit different, a few hundred more pF to C81 maybe be perfect, or it may require more or less e.g. experimentation may be necessary.
73,
Mark
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Re: uBitx v.4 build information
Mark
perhaps she made other adjustments, as mine improved greatly with just a few hundred pF added at C81.? please see Asshar's post about C81, I think my adjustment is consistent with what he was recommending for the FEW v4's that have a dip at 40m.?
Curt
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Re: uBitx v.4 build information
Hi Vic,
Adding 0.1uF will result in basically no frequency compensation for Q90.? Looking at past posts, Allison ended up with a total of 1100pF for C81.
73,
Mark
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_Dave_ AD0B
Vic WA4THR