Sbitx v4.4 es Xiegu amp
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On Sat, Mar 8, 2025 at 11:03 AM, Doug Backer wrote:
Is the anyone running a Xiegu XPA125B with there Sbitx v4.4 with Jeff's QRO board? If so can you give me the "run down" do's/don'ts? Drive power ect ect... The QRO board should be here today I have an MX-P150 running, I send out a maximum of 60 Watts in FT8 mode, when the input is approx. 6 Watts.
The sbitx drive=9-10 (depending on the wave propagation) at 14 MHz, while the drive=20-22 at 21 MHz, to have a similar output power.
The sbitx retains the drive value even when turned off, but it is worth noting it and starting from a low value.
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Gyula HA3HZ |
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ps.: As usual, I feed the PA from a reverse current-limiting power supply. I do this because I don't like to touch a soldering iron often for repairs.?
In my case, the PA receives 12.5V and I limit the current consumption at 12.0A.?
I don't know the operating options of the PA you wrote about, so start from a low value if you want to limit the current consumption.?
The sbitx v2 also operates with a similar current limitation. At a supply voltage of 12.5V, I limit the current consumption to 6.5A (this is a different power supply).?
I only have one antenna that can work well at 7-14-21 MHz, without an antenna tuner.?
It is an obliquely mounted delta loop, which is fed at its highest point through 2 ferrite ring joints.?
20 Watts was enough to connect to 3D2CCC (Conway Reef) from a distance of more than 16 thousand km in the summer.
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Gyula HA3HZ |
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On Sat, Mar 8, 2025 at 03:23 PM, Kevin wrote:
Is there a particular current limiting power supply that you recommend for the sbitx?? I don't typically see HAM linear or switching power supplies with amp adjustments and the one that I have looks like a scientific bench model from the 60s.? I use a Wantek switching power supply (30V 10A max.), which I filter with 2x 6 turns on FT140-43 ferrites and 1nF II 100nF capacitors at the input connector of the sbitx. The power supply is grounded only at the mains connector. The positive and negative wires run in parallel with 6 turns and the wire has a cross section of 2.5 mm2. The two capacitors are at the power connector. There are M4 threaded holes on the back of the device, one of which I use to attach the ground wire. The antenna is fed with RG8X coax and on the loop side there is 100/50 Ohm and a symmetrical/asymmetrical adapter on FT240-43 ferrites.
The final stage PSU has a current limiter of 30V 20A. On the PA power input there is 2x 6 turns on the same FT140-43 ferrite and the capacitors.
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Gyula HA3HZ |
开云体育Current limiting an amp is not necessarily a good thing… can generate compression for no good reason.? Its better to drive limit an amplifier. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of JJ - W9JES
Sent: Saturday, March 8, 2025 7:35 PM To: [email protected] Subject: Re: [BITX20] Sbitx v4.4 es Xiegu amp ? On Sat, Mar 8, 2025 at 08:23 AM, Kevin wrote:
Current limiting can be achieved in several ways even with a traditional HAM power supply. Just put fuses inline between the radio and power supply. Make sure you fuse both the positive and negative side with an appropriate fuse. The sBitx V3 draws up to 9 amps on TX at high power on some bands. A 10a fuse would be fine in this case. You can also swap to a lower amperage fuse as needed. ? JJ |
HA3HZ
Kevin
K9HZ
On Mar 8, 2025, at 20:43, K9HZ via groups.io <bill@...> wrote:
?Current limiting an amp is not necessarily a good thing… can generate compression for no good reason.? Its better to drive limit an amplifier.
?
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Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ
?
Owner - Operator
Big Signal Ranch – K9ZC
Staunton, Illinois
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Owner – Operator
Villa Grand Piton – J68HZ
Soufriere, St. Lucia W.I.
Rent it:
?
Moderator: North American QRO Group at Groups.IO.
Moderator: Amateur Radio Builders Group at Groups.IO.
?
email:? bill@...
?
?
From: [email protected] <[email protected]> On Behalf Of JJ - W9JES
Sent: Saturday, March 8, 2025 7:35 PM
To: [email protected]
Subject: Re: [BITX20] Sbitx v4.4 es Xiegu amp?
On Sat, Mar 8, 2025 at 08:23 AM, Kevin wrote:
Is there a particular current limiting power supply that you recommend for the sbitx?? I don't typically see HAM linear or switching power supplies with amp adjustments and the one that I have looks like a scientific bench model from the 60s.?
Current limiting can be achieved in several ways even with a traditional HAM power supply. Just put fuses inline between the radio and power supply. Make sure you fuse both the positive and negative side with an appropriate fuse. The sBitx V3 draws up to 9 amps on TX at high power on some bands. A 10a fuse would be fine in this case. You can also swap to a lower amperage fuse as needed.
?
JJ