Re: [Elecraft] KPA-1500 power supply fan noise

I believe he is talking about PS fans, which is not on the menu. However, there is a mod kit from Elecraft that includes the resistor. It is very easy to install. No soldering is required, and the most time-consuming part of the install is removing the cover. Contact Elecraft support and they

Re: [Elecraft] KPA-1500 power supply fan noise

Sorry, I missed that you were concerned with the PSU. I've never heard them because the fan(s) on the RF deck are so loud. :) 73, Jim On 5/23/2020 1:22 PM, Peter Dougherty wrote: Nothing in my manual (Revision B1, February 12, 2019).

Re: [Elecraft] KPA-1500 power supply fan noise

: elecraft-boun...@mailman.qth.net On Behalf Of Eric Swartz WA6HHQ - Elecraft Sent: Saturday, May 23, 2020 11:53 AM To: Larry (K8UT) Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 power supply fan noise Hi Peter, If the amp is on, there needs to be at least some PS fan activity

Re: [Elecraft] KPA-1500 power supply fan noise

to be expected, alas. - pjd From: Morgan Bailey Sent: Saturday, May 23, 2020 2:11 PM To: Peter Dougherty Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 power supply fan noise Head to walmart and buy a box of cheap hot pink foam ear plugs that have 30 db noise

Re: [Elecraft] KPA-1500 power supply fan noise

to be expected, alas. - pjd From: Morgan Bailey Sent: Saturday, May 23, 2020 2:11 PM To: Peter Dougherty Cc: Elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 power supply fan noise Head to walmart and buy a box of cheap hot pink foam ear plugs that have 30 db noise

Re: [Elecraft] KPA-1500 power supply fan noise

On 5/23/2020 7:33 AM, Peter Dougherty wrote: Is there any way to power off the fans (or lower their RPM) on the PSU if the amp is in standby mode? You did read the manual, right? Fan speed is on the menu. 73, Jim K9YC __ Elecraft

Re: [Elecraft] KPA-1500 power supply fan noise

Head to walmart and buy a box of cheap hot pink foam ear plugs that have 30 db noise reduction. Or have her wear earbuds to a new ipod listen to music...sign her up for pandora. LOL Vy 73, Morgan NJ8M On Sat, May 23, 2020 at 9:35 AM Peter Dougherty wrote: > Is there any way to power off the

Re: [Elecraft] KPA-1500 power supply fan noise

- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Eric Swartz WA6HHQ - Elecraft Sent: Saturday, May 23, 2020 10:53 AM To: Larry (K8UT) Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 power supply fan noise Hi Peter,

Re: [Elecraft] KPA-1500 power supply fan noise

amplifier (about 3 feet longer if I recall correctly). > > This allows the PS to operate "remote" in a closet with the door closed. > > -larry (K8UT) > > -- Original Message -- > From: "Peter Dougherty" > To: Elecraft@mailman.qth.net >

Re: [Elecraft] KPA-1500 power supply fan noise

om: "Peter Dougherty" To: Elecraft@mailman.qth.net Sent: 2020-05-23 10:33:19 AM Subject: [Elecraft] KPA-1500 power supply fan noise Is there any way to power off the fans (or lower their RPM) on the PSU if the amp is in standby mode? I would like to keep my rig on 6m throughout the day

Re: [Elecraft] KPA-1500 power supply fan noise

HI Peter, Put the 6M antenna on Antenna Port 1 for now. 73, Mitch NWØM -- Sent from: http://elecraft.365791.n2.nabble.com/ __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help:

[Elecraft] KPA-1500 power supply fan noise

Is there any way to power off the fans (or lower their RPM) on the PSU if the amp is in standby mode? I would like to keep my rig on 6m throughout the day during the Es season. The problem is my 6m antenna is on antenna port 2 on the KPA, which requires the amp to be powered up. I only need to TX

Re: [Elecraft] KPA-500 Fault - follow up

You will need the KAT500 Utility to perform a reset to factory values.   That software is a free download on the Elecraft site. While you are at it, download all the various software's for each piece of equipment.  i.e.  K3, P3, KPA500, KAT500.  They allow you to save parameters, change

[Elecraft] KPA-500 Fault - follow up

All, I tried to firmly seat all of the connectors. No change. I finally pulled them out and only used the keying cable (RCA to RCA). No change. One thing I noticed is that the KAT 500 was giving me Power and SWR reading, but no amplification from the amplifier. And if I had any more than

[Elecraft] KPA 500 6meter power out.

I have had this problem for some time but as I almost never use 6 meters it has not really concerned me. I have two identical K Line stations, K3's, KAT 500's, KPA 500's and P3's. On station #1 everything works as it should and if I put 25 watts into the KPA 500 I get 500+ watts out. On station

Re: [Elecraft] KPA-500 Issues

What is the SWR? If above the KAT500 set value it inhibits the amp from being keyed. Check the KAT500 using the ATU utility. Bob, K4TAX Sent from my iPhone > On May 15, 2020, at 1:50 PM, Jack Brindle via Elecraft > wrote: > >  > Check the cable connections, including making sure that

Re: [Elecraft] KPA-500 Issues

Check the cable connections, including making sure that none of the pins are bent in the AuxIO connectors in both cables (K3S - KAT500, KAT500 - KPA500). Also, make sure that the PTT line is actually being asserted. The asterisk is displayed when the Key In is asserted. If it isn’t displayed

Re: [Elecraft] KPA-500 Issues

That implies that the AUX cable is not working.  Cycle the gear power and make sure each connector is properly seated. Rick NK7I On 5/15/2020 11:07 AM, Edward via Elecraft wrote: I have the combo K3S/KAT500/KPA500 with all of the optional interconnection cables. I am not able to key the

[Elecraft] KPA-500 Issues

I have the combo K3S/KAT500/KPA500 with all of the optional interconnection cables. I am not able to key the amp though it was working earlier. The asterisk does not appear in the display. I went through the menu and everything is set accordingly. The inhibit is disabled. Any help would

[Elecraft] KPA-500 and KAT-500 Wanted

Looking for KPA-500 and KAT-500. Does not need to be a package deal. Contact me at jimlc...@gmail.com . 73, Jim W2SM __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help:

Re: [Elecraft] KPA 500 fault!

Thanks! I found the earlier manual online, and am back operational! Thanks! Tom W4KX > On May 3, 2020, at 4:14 PM, iain macdonnell - N6ML wrote: > > On my early model, the interlock switch is actuated by an assembly > including a 13mm 4-40 standoff (and some other hardware), which is >

Re: [Elecraft] KPA 500 fault!

Ian, Could you also send me a copy, I have an older amp as well. 73, and thanks, Dave (NK7Z) https://www.nk7z.net ARRL Volunteer Examiner ARRL Technical Specialist ARRL Asst. Director, NW Division, Technical Resources On 5/3/20 1:14 PM, iain macdonnell - N6ML wrote: On my early model, the

Re: [Elecraft] KPA 500 fault!

On my early model, the interlock switch is actuated by an assembly including a 13mm 4-40 standoff (and some other hardware), which is attached to the inside of the top cover. I'll attempt to send you the old (rev C) assembly manual off-list. 73, ~iain / N6ML On Sun, May 3, 2020 at 1:07 PM

Re: [Elecraft] KPA 500 fault!

Problem is definitely the interlock switch not being engaged correctly: if I close it manually (with a wooden rod!) the amp operates normally. Anyone have an assembly manual for the older type KPA500, so I can see how the top-panel interlock switch is supposed to be engaged? Again, this a

Re: [Elecraft] KPA 500 fault!

Hi Jack! After cycling the main power the HV in standby is back to 70 V. But, every time I go to operate mode, the error reoccurs. This is with what I believe was the old style interlock switch (has a shaft attached to the top cover to engage the switch when the top is screwed down). Can’t

Re: [Elecraft] KPA 500 fault!

A “270V ERR” fault indicates that the TR switch bias supply is not working. This may be caused by the top cover being removed, the safety switch attached to the top cover becoming loose or an actual failure of the 270V supply. Since your main HV supply is now down close to 0V, it looks like you

[Elecraft] KPA 500 fault!

My KPA500 has been working fine waited for 115 V. Just now it has been throwing a “25=70 VAC” fault! Can anyone lead me in helping this? Fuses look good. HV read 0.1 v when in standby, which is FAR from the 70 some volts it used to read. Thanks! Tom W4KX

Re: [Elecraft] KPA 500

"60 deg C with fan not running is not normal.  60 deg C is the nominal temperature for start of fan speed 3." The conversation was continued off "list" but there are a few points that I'd like to be in the archive -  There would appear to be two possible failure conditions.  Either the fan is

Re: [Elecraft] KPA 500

Brown > Sent: Friday, April 10, 2020 11:27 AM > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] KPA 500 > > On 4/10/2020 8:45 AM, Irwin Darack wrote: > > In my experience, coax connectors, barrel connectors, etc. are always > > fail points when there is a sudden increa

Re: [Elecraft] KPA 500

: elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA 500 On 4/10/2020 8:45 AM, Irwin Darack wrote: > In my experience, coax connectors, barrel connectors, etc. are always > fail points when there is a sudden increase in SWR as power is > increased. They oxidize over time and sometime

Re: [Elecraft] KPA 500

To: elecraft Sent: Fri, Apr 10, 2020 1:23 pm Subject: Re: [Elecraft] KPA 500 A vendor at Dayton told me *all* are made in China, even the ones marked Amphenol. k4ia, Buck K3s# 11497 Honor Roll  8B DXCC EasyWayHamBooks.com On 4/10/2020 12:43 PM, Irwin Darack wrote: > Agreed. Many people

[Elecraft] KPA 500

"After transmitting at 200W the temperature slowly rises above 60 degrees C, but the fan doesn't cut in. Does anyone know if this is normal behavior and what temperatures I should expect to see?" Nominal temperature for start of fan speed 1 is 50 deg C although my data for one test run showed

Re: [Elecraft] KPA 500

That’s likely true. But if he’s saying they’re the same as Chinese brand, that’s nonsense. I use a lot of connectors from Amphenol Audio which are made in China. The difference between Amphenol & equivalent Chinese is obvious on inspection. Mating is very solid and contact plating looks much

Re: [Elecraft] KPA 500

-Original Message- From: Lyn Norstad [mailto:l...@lnainc.com] Sent: Friday, April 10, 2020 8:59 AM To: 'Alan - G4GNX'; 'Elecraft Reflector' Subject: RE: [Elecraft] KPA 500 At 100w on 20m, my KAT500 Utility shows an SWR of 1.00 with the KPA500 on Standby and temp around 38ºC. But as I switch

Re: [Elecraft] KPA 500

On 4/10/2020 10:19 AM, Buck wrote: A vendor at Dayton told me *all* are made in China, even the ones marked Amphenol. Um, Apple products have long been made in China. Fair-Rite has had one or more factories in China for more than a decade. "Made in China" does NOT define the product as junk.

Re: [Elecraft] KPA 500

: [Elecraft] KPA 500 I am watching this with great interest. If running stations on CW my KPA500 shows low-mid 50sC and I have never known what it should be. Thanks everyone. On Fri, Apr 10, 2020 at 10:27 Randy Farmer wrote: If the initial VSWR is really measuring 1.00:1 with low power

Re: [Elecraft] KPA 500

I try and spend the time to recover OLD PL-259 connectors.  I have some which I've owned for 30 to 40 years.  They are ugly, tarnished, and may have phenolic insulatorsbut are darn good connectors.    When I encounter a bad or connector, I usually chop the connector off with about 1"

Re: [Elecraft] KPA 500

Amphenol more than likely does QC... So I would expect the majority of their connectors to be better than the possibly non QC tested connectors. I doubt most resellers QC the connectors. I am sure some do, but I would love to know which ones do. 73, and thanks, Dave (NK7Z)

Re: [Elecraft] KPA 500

A vendor at Dayton told me *all* are made in China, even the ones marked Amphenol. k4ia, Buck K3s# 11497 Honor Roll 8B DXCC EasyWayHamBooks.com On 4/10/2020 12:43 PM, Irwin Darack wrote: Agreed. Many people buy the cheap ones made in Chinaand they fail. Irwin KD3TB On Fri, Apr 10, 2020

Re: [Elecraft] KPA 500

My first question is "what does it do on a dummy load?"  Sounds like something related to a bad or questionable jumper cable, loose connector or bad connectors.   I find many of today's connectors have machining tolerance errors and more so, have only "good looking" plating.  While in fact,

Re: [Elecraft] KPA 500

Agreed. Many people buy the cheap ones made in Chinaand they fail. Irwin KD3TB On Fri, Apr 10, 2020 at 12:28 PM Jim Brown wrote: > On 4/10/2020 8:45 AM, Irwin Darack wrote: > > In my experience, coax connectors, barrel connectors, etc. are always > fail > > points when there is a sudden

Re: [Elecraft] KPA 500

On 4/10/2020 8:45 AM, Irwin Darack wrote: In my experience, coax connectors, barrel connectors, etc. are always fail points when there is a sudden increase in SWR as power is increased. They oxidize over time and sometimes just reconnecting or replacing is the first step before taking the amp

Re: [Elecraft] KPA 500

In my experience, coax connectors, barrel connectors, etc. are always fail points when there is a sudden increase in SWR as power is increased. They oxidize over time and sometimes just reconnecting or replacing is the first step before taking the amp apart. Irwin KD3TB On Fri, Apr 10, 2020 at

Re: [Elecraft] KPA 500

I am watching this with great interest. If running stations on CW my KPA500 shows low-mid 50sC and I have never known what it should be. Thanks everyone. On Fri, Apr 10, 2020 at 10:27 Randy Farmer wrote: > If the initial VSWR is really measuring 1.00:1 with low power, that > means the

Re: [Elecraft] KPA 500

at 5 KW. 73 Lyn, WØLEN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Alan - G4GNX Sent: Friday, April 10, 2020 6:27 AM To: Elecraft Reflector Subject: [Elecraft] KPA 500 I have a strange fault a couple of times recently

Re: [Elecraft] KPA 500

If the initial VSWR is really measuring 1.00:1 with low power, that means the detected reflected power is exceptionally low. I'm sure the algorithm used to compute SWR sets it to 1:1 if there's zero reflected power. If the load is not really perfectly flat, as the incident power is increased

Re: [Elecraft] KPA 500

Alan, That does sound like an antenna problem - balun heating, a loose or bad connection somewhere. Try that same test into a dummy load - if it shows the same behavior, then you can blame the KPA500, but if not blame the antenna system. 73, Don W3FPR On 4/10/2020 7:26 AM, Alan - G4GNX

Re: [Elecraft] KPA 500

My experience is that slowly increasing SWR is from a component heating up, usually an inductor in a tuner or balun. You don't see it with lower power. Ferrite cores change their inductance radically as they heat up near their Curie temperature. If they get to their Curie temperature, they lost

Re: [Elecraft] KPA 500

I would be more likely to suspect something after the KPA500, such as the tuner or a balun. I've experienced significant balun heating, especially when using a balun other than a straight-through 1:1 balun, or when the load is highly reactive. Balun power ratings assume a non-reactive load.

Re: [Elecraft] KPA 500

are rated at 5 KW. 73 Lyn, WØLEN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Alan - G4GNX Sent: Friday, April 10, 2020 6:27 AM To: Elecraft Reflector Subject: [Elecraft] KPA 500 I have a strange fault a couple of times recently

[Elecraft] KPA 500

I have a strange fault a couple of times recently, where the SWR starts to increase during the time of a single 'over'. I've been using the K3S set at 100W out, via the KPA500 (in standby) and the KAT500 tuner, without any problem, but after I've switched the linear to Operate and driving

[Elecraft] KPA-1500 PS pics?

Anyone have link/s to INTERNAL photos of the KPA-1500PS?   No find on google image search.   73, Mike AC5P __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post:

Re: [Elecraft] KPA-1500 efficiency with a Low-Power Setting

The bias would do nothing for low power. Low power can be implemented in two ways, with different taps at final transformer (KX3), and with different supply voltage (Expert amps). The first one is hard at a KW level. The second one requires power supply with different voltages. If the power

Re: [Elecraft] KPA-500 Switch from STBY to OPER

Bill, No relays in the T/R switching path for the KPA500 - all solid state switching. 73, Don W3FPR On 2/10/2020 6:39 PM, Bill Weaver wrote: If there is a relay in the rx signal path, check the contacts. I had that happen with my Alpha recently. Of all the possibilities that was the

Re: [Elecraft] KPA-500 Switch from STBY to OPER

If there is a relay in the rx signal path, check the contacts. I had that happen with my Alpha recently. Of all the possibilities that was the easiest thing to fix. Thankfully that was the problem :-). 73, Bill WE5P ⁣Get BlueMail for Android ​ On Feb 10, 2020, 17:52, at 17:52,

Re: [Elecraft] KPA-500 Switch from STBY to OPER

Sounds as though the TR switching has failed. Contact Elecraft support. Bob, K4TAX Sent from my iPhone > On Feb 10, 2020, at 5:05 PM, afpac...@gmail.com wrote: > > I am looking for thoughts and suggestions to diagnosis what I am seeing. > When the amp is changed from STBY to OPER the

[Elecraft] KPA-500 Switch from STBY to OPER

I am looking for thoughts and suggestions to diagnosis what I am seeing. When the amp is changed from STBY to OPER the receive signal drops by multiple db and the general background seems to increase significantly. The tuner seems to work the same with or without the amp. When I transmit it

[Elecraft] KPA-1500 efficiency with a Low-Power Setting

I would like to see the KPA-1500 have a "Medium Power" setting with optimized bias for that power level so the amp could be operated at 750-watts output and good efficiency.  While the KPA-1500 can operate FT and RTTY contests at 1,500 watts, I believe the amp operated at 750-watts with an

[Elecraft] KPA-1500 and Praise for Elecraft Support

I just can't resist writing this.  If you're tired of praise for Elecraft, please delete. I bought myself a KPA-1500 for Christmas, 2018.  It worked just fine, though with a couple of quirks.  In particular, I had two quite dissimilar antennas for 40M, and while working Assisted S with

[Elecraft] KPA 1500 Question

Hello All, Does anyone know if there are any issues with the KPA 1500 when used in a multi transmitter contest environment?? Thanks in advance for any info of input on this!! 73, Ted  K2QMF Meghan Markle Confirms Unfortunate News

[Elecraft] KPA-500 Remote Program

Hi: Hopefully everyone had a good Christmas and Happy New Year. Just curious FWIW, I just can't seem to get the KPA500 Remote program to work. I can get the KAT500 and the KPA1500 to work, but the KPA500 refuses to load. It says "Unable to load specified amp driver". I am using the latest

Re: [Elecraft] KPA 1500 and receiver noise

: Monday, December 30, 2019 10:39 AM To: K0RKH ; elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA 1500 and receiver noise Hi Bob. Contact support(at)elecraft.com and request the free KPA1500 power supply load resistor kit. They can also tell you if your amp S/N was manufactured before we

Re: [Elecraft] KPA 1500 and receiver noise

Hi Bob. Contact support(at)elecraft.com and request the free KPA1500 power supply load resistor kit.  They can also tell you if your amp S/N was manufactured before we started adding the load resistor to new units some time ago. 73, Eric /elecraft.com/ On 12/30/2019 8:12 AM, K0RKH wrote:

Re: [Elecraft] KPA 1500 and receiver noise

Thank You to the replies I have recieved on this subject. When I get back home in a few days I will look for the electrical hash again with the fan on. I am guessing that this would point to the suggestion of some slight loading of the power supply to smooth out emitted noise.

Re: [Elecraft] KPA 1500 and receiver noise

My 1500 had birdies which were reduced with adding load resistor to the 50 volt supply on the amp. Still present but much lower. Dave wo2x Sent from my waxed string and tin cans. > On Dec 29, 2019, at 1:26 PM, K0RKH wrote: > >  I am looking for possible causes of increased

[Elecraft] KPA 1500 and receiver noise

I am looking for possible causes of increased receive noise I am experiencing whenever I turn on my KPA 1500 . I have always had this issue but at first disregarded it as maybe common mode noise but have since experimented a bit by connecting a dummy load to the receiver and

[Elecraft] WTB Elecraft KPA 500 Amp.

I am looking to buy an Elecraft KPA 500 amplifier. Needs to be in good condition and perfect working order. Please contact me at with info and asking price. Thanks for reading, Mike, WM5DX. __ Elecraft mailing list Home: http

[Elecraft] KPA-500 failure

Anyone else have their KPA-500 crash on power ON?   All LED's briefly flash then all dead.  Main fuses good.   73,  Mike AC5P __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help:

[Elecraft] KPA-1500 ATU operation

Thanks to Dick for the detailed explanation of the tuner. I didn't know about the 8 Kc resolution limitation of the tuner. Even with plus or minus 8 Kc I should still be with a segment or two of the actual frequency, so I should be lower than 1.5:1 SWR. Thanks everyone. Charles K5UA

Re: [Elecraft] KPA-1500 ATU operation

"If it were up to me, I would not allow the counter to have priority unless the frequency difference is at least several bin's worth. That way, transmission wouldn't be needlessly interrupted because of the low counter resolution, but the amp would still be protected against erroneous data from

Re: [Elecraft] KPA-1500 ATU operation

One thing that may confuse things is that the frequency counter has only 8 kHz (?) resolution, and it takes priority over data from the radio. I'm unsure about this, as my KPA1500 doesn't often seem to change ATU setting when start transmitting. It is possible, though, that the low resolution

Re: [Elecraft] KPA-1500 ATU operation

Yes I got caught with using reference to an older manual on this topic. my oops Bob, K4TAX Sent from my iPhone > On Dec 11, 2019, at 11:50 AM, char...@k5ua.com wrote: > > I should have checked for a new manual since the manual that came with my > KPA-1500 has 20 Kc bins which I see are

[Elecraft] KPA-1500 ATU operation

I should have checked for a new manual since the manual that came with my KPA-1500 has 20 Kc bins which I see are now 10 Kc bins. In addition, the tuning frequencies have been changed to 10 Kc increments. I think that is why I was getting unexplained results from the tuner as I tuned across

[Elecraft] KPA-1500 ATU operation

"If you are polling the transceiver and have fairly recent version of firmware, the ATU will change frequency at the boundary of the segment, with no hysteresis. Twiddle your VFO knob in standby and you will here the relays clicking right at the edges." An explanation of how the tuner follows

Re: [Elecraft] KPA-1500 ATU operation

...@mailman.qth.net On Behalf Of Bob McGraw K4TAX Sent: Wednesday, December 11, 2019 02:08 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 ATU operation The ATU uses 10 kHz segments below 3 MHz. And then 20 kHz segments 3 MHz through 26 MHz. And 100 kHz segments from 38 MHz through 30 MHz

Re: [Elecraft] KPA-1500 ATU operation

the segments are 100 kHz wide. • Above 38 MHz the segments are 200 kHz wide. Mark, WB9CIF -Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of Bob McGraw K4TAX Sent: Wednesday, December 11, 2019 02:08 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 ATU

Re: [Elecraft] KPA-1500 ATU operation

The ATU uses 10 kHz segments below 3 MHz.  And then 20 kHz segments 3 MHz through 26 MHz.   And 100 kHz segments from 38 MHz through 30 MHz.   And 200 kHz segments 38 MHz through 60 MHz. The understanding regarding 80M would then be the segments are 20 kHz wide and not 10 kHz wide. 73 Bob,

Re: [Elecraft] KPA-1500 ATU operation

At 03:03 PM 12/10/2019, char...@k5ua.com wrote: Does anyone have information on how the ATU is supposed to work when it is polling the xcvr for frequency? If you are polling the transceiver and have fairly recent version of firmware, the ATU will change frequency at the boundary of the

Re: [Elecraft] KPA-1500 ATU operation

I understand that the ATU uses 10 kHz segments on 80, which was at some point changed from 20 kHz. That means the center points are 3505, 3515, etc. There is some hysteresis when tuning, but I'm not sure that consistently explains where it switches. It also won't switch until you stop tuning

Re: [Elecraft] KPA-1500 ATU operation

Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of char...@k5ua.com Sent: Tuesday, December 10, 2019 15:04 To: elecraft@mailman.qth.net Subject: [Elecraft] KPA-1500 ATU operation After saving my KPA-1500 ATU impedance matching parameters on 80M at 20 Kc intervals (3.510,

[Elecraft] KPA-1500 ATU operation

After saving my KPA-1500 ATU impedance matching parameters on 80M at 20 Kc intervals (3.510, 3.530, 3.550, 3.570, etc, etc), I expected that the KPA-1500 ATU would automatically switch to the next set of L/C values at the midpoint of the 20 Kc segments (like 3.520, 3.540, 3.560, etc, etc), but

Re: [Elecraft] KPA-1500 wish list

On 11/20/2019 8:06 PM, N4ZR wrote: Yup, but old habits die hard! Old dogs like us have to continue learning new tricks. :) You've done a LOT of that helping to build and teach us all about RBN. 73, Jim K9YC __ Elecraft mailing

Re: [Elecraft] KPA-1500 wish list

Yup, but old habits die hard! 73, Pete N4ZR Check out the Reverse Beacon Network at , now spotting RTTY activity worldwide. For spots, please use your favorite "retail" DX cluster. On 11/20/2019 2:09 PM, Jim Brown wrote: The simple solution to this is to TX a dit

Re: [Elecraft] KPA-1500 wish list

The simple solution to this is to TX a dit before making the call. I've done this for years when working with auto-detect equipment like the KAT500, KPA500, and 87A. On SSB, the equivalent is to tap the mic. 73, Jim K9YC On 11/20/2019 6:40 AM, N4ZR wrote: I'd love to have 50-ohm resonant

Re: [Elecraft] KPA-1500 wish list

When you QSY, without switching antennas, it seems to take half a second or so after you stop tuning for the ATU to switch. (Assuming it's been "trained".) As far as I can tell, after that delay the ATU is stable, so it shouldn't affect outgoing CW. However, as Pete says, when you switch

Re: [Elecraft] KPA-1500 wish list

I hope that the amp guys at Elecraft will reply to this thread.  I've been working with them for several weeks trying to address just this problem.  The latest beta firmware seems to handle it pretty well, so long as I make sure I've trained the ATU on every band segment. I'd love to have

Re: [Elecraft] KPA-1500 wish list

Bill is touching on an issue I've raised before: A way to select multiple ATU settings for the same frequency and antenna output. I had to build a tri-band tuner to switch between my two tribanders so they would both present the amplifier with the same impedance. The internal ATU would have

Re: [Elecraft] KPA-1500 wish list

. The possibilities are staggering! 73 Lyn, WØLEN -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of K9MA Sent: Monday, November 18, 2019 10:00 PM To: Paul Baldock; elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500

Re: [Elecraft] KPA-1500 wish list

Another issue not explicitly mentioned is using an external antenna switch with different conjugate matches already trained withing the KPA1500 ATU. Those different matches mean when one selects a "new" (different) antenna than already selected on a particular frequency (same band or not), the

Re: [Elecraft] KPA-1500 wish list

Gain control within the KPA1500 just wouldn't be practical. It would require addition of some sort of high power variable attenuator. Slow feedback to the K3, however, only requires some added firmware. No, it wouldn't work with other transceivers, but that's life. Perhaps someone would like

Re: [Elecraft] KPA-1500 wish list

"Yes, ALC that really worked well with an amplifier would make the above unnecessary, but I don't think anyone has figured out how to do that. Until someone does, a slow feedback loop adjusting drive power would solve the problem above, not introduce any distortion, and save us operators the

Re: [Elecraft] KPA-1500 wish list

On 11/18/2019 21:52, Paul Baldock wrote: I also have WET and DRY settings for one of my antennas that are selected by PF1 (^PB). Ah, but there can be more than two setting. A little wet, or a lot wet. Or, in the case of one of my antennas, varying amounts of frost. 73, Scott K9MA -- Scott

Re: [Elecraft] KPA-1500 wish list

By "manually tuning" I mean using KPA1500 Utility program to tweak the L and C. In most cases you can get closer to zero reflected power than the automatic routine can. Getting the SWR down as close as possibly to 1.0:1 at all frequencies most certainly flattens the gain/frequency response.

Re: [Elecraft] KPA-1500 wish list

There are a couple issues here. First, even if the SWR is 1.2:1, about the best the KP1500 ATU firmware can do, across the whole band, the power can still vary a lot. It depends on the actual load impedance, which, at 1.2:1 could be anywhere from 42 to 60 Ohms. If you happened to be at 42

Re: [Elecraft] KPA-1500 wish list

Jim, I think Paul is talking about something different here.  On Page 18 of the manual it describes tapping the ATU Tune button again within 3 seconds of completing the initial tune, to get closer yet.  I just tried it, and it works well so long as you have trained the tuner for both antennas

Re: [Elecraft] KPA-1500 wish list

Yes and I have trained my tuner to use the same frequency on different antennas.  Thus when I switch antennas it does not require any re-tuning, only push the ANT selector for the preferred antenna of choice at the moment. 73 Bob, K4TAX On 11/18/2019 7:18 PM, Jim Brown wrote: On

Re: [Elecraft] KPA-1500 wish list

On 11/18/2019 11:34 AM, Paul Baldock wrote: I have manually tweaked (with amp in standby and running 50W) my auto learned atu settings to get as close to 0W reflected power as possible. Yes, and this is exactly what the manual says to do -- before using the amp, train the tuner by tuning at

Re: [Elecraft] KPA-1500 wish list

In my experience for the amplifier gain to be flat across a band it requires the output SWR to 1.1:1 or better. So the solution is to use the internal tuner on all frequencies that you do not have a perfect match. I have manually tweaked (with amp in standby and running 50W) my auto learned

[Elecraft] KPA-1500 wish list

"(It could also be done entirely external to the KPA1500 by replicating its power sensing circuitry, a bit of a waste.) It's not trivial but I'm convinced it's possible." I'm no expert on amplifier design but wouldn't it be more appropriate to have (slow) closed loop control of the amplifier

Re: [Elecraft] KPA-1500 wish list

Sent: 18 November 2019 18:08 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] KPA-1500 wish list At risk of starting a FIRE storm here in the group, why not CORRECTLY configure the ALC between the amp and radio.  Just remember it is not a power control application but no different than

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