?

I see some of you are running firmware 1.07b. How did you get that version? The latest version on the web site is 1.05k, which is what I have.

Also as to the comment about my antenna, note that it is usually running through the HF-AUTO, which continuously shows a matched SWR of 1.1 or better, and never something like 1.8. And I use a direct connect cable from my FT-DX3000.

I am rapidly loosing confidence in the so-called great support by Palstar. I wish I had the ability to put up a completely different antenna to try, but I do not.

From: [email protected] [mailto:[email protected]] On Behalf Of davenlr@...
Sent: July 12, 2020 8:42 PM
To: [email protected]
Subject: Re: [la1k] Keying Relay Buffer Debate

?

Can you only write to the firmware chip, or can you download/backup the firmware and send it to another user?

Would like to get a discussion going on if it is necessary to use a Keying Relay Buffer when using the Palstar LA1K Amp. I called Palstar this week and talked with one of their technicians and told him I was planning on getting an LA1K amp in the near future.? I told him that I am using an Icom IC-7300. My question to the tech was do I need to use a Keying Buffer in between the LA1K and the IC-7300.
Palstar told me it wasn't necessary and that I just needed to use one RCA cable and connect it to the PTT connection. He also said to keep the transmit power on the exciter to 40 watts. Comments, suggestions greatly appreciated.

Mike.

It's true that there is no need to institute a keying delay in this amp.? There are built in timers in the LA1K that prevent hot switching.?? Here's what happens...

1, Amp senses the keying line going to ground, (nothing happens, you may see "Wait" on the display)

2. At first sign of RF amp reads the frequency, switches to the appropriate Low Pass filter.

3. When it verifies filter selection it signals to close the T/R relay.

4. When T/R closure is verified, ONLY then does it allow RF to be applied to the devices.

?? This all happens in 8 to 15 milliseconds.? So applying an additional delay in the Xcvr only slows the process down.? There is excellent reason for keying delay to be built in to some radios since many amps out there do not employ such a sophisticated timing sequence and can be hot-switching all of the time.

73,

Dennis

N0SP

On 7/11/2020 at 12:46 PM, mmang2758@... wrote:

Would like to get a discussion going on if it is necessary to use a Keying Relay Buffer when using the Palstar LA1K Amp. I called Palstar this week and talked with one of their technicians and told him I was planning on getting an LA1K amp in the near future.? I told him that I am using an Icom IC-7300. My question to the tech was do I need to use a Keying Buffer in between the LA1K and the IC-7300.
Palstar told me it wasn't necessary and that I just needed to use one RCA cable and connect it to the PTT connection. He also said to keep the transmit power on the exciter to 40 watts. Comments, suggestions greatly appreciated.

Mike.

Interesting. I am also having the same bypass issue, but only when I am using fldigi to send some message. 80m is the worst example, and is totally useless. In addition I am using the HF-AUTO tuner, which is always showing an SWR in the range 1.05 to 1.1, and the amp is showing SWR in the range of 1.2 to 1.3 when things are working correctly, but it does jump up to 1.8 and then instantly goes into bypass mode. Major PITA. Discussions with Mark did not elicit any comments about this being a known problem, basically stated it had something to do with my antenna, but I could always send the units in to be checked out. Also I tried adding a Palomar (?) choke balun to see if that helped (I already have a loop of coax at the antenna and many beads at both ends) and that made no difference other than to increase my normal SWR about .02 or so. Tried skipping the HF-AUTO and my antenna is natively about 1.6, and it still kicks out.

Sadly I have stopped recommending this equipment to others because of this issue. They are good units, and as this group has shown they are not the only ones that do this, but denying the problem will not help get things solved. SSB works fine here with no issues of this nature. Also my local HRO has sold the identical equipment (2 set-ups!) to another ham, and he has no problems, but I am not sure if he is doing any digital modes.

Al? KD2PNR

It's true that there is no need to institute a keying delay in this amp.? There are built in timers in the LA1K that prevent hot switching.?? Here's what happens...

1, Amp senses the keying line going to ground, (nothing happens, you may see "Wait" on the display)

2. At first sign of RF amp reads the frequency, switches to the appropriate Low Pass filter.

3. When it verifies filter selection it signals to close the T/R relay.

4. When T/R closure is verified, ONLY then does it allow RF to be applied to the devices.

?? This all happens in 8 to 15 milliseconds.? So applying an additional delay in the Xcvr only slows the process down.? There is excellent reason for keying delay to be built in to some radios since many amps out there do not employ such a sophisticated timing sequence and can be hot-switching all of the time.

73,

Dennis

N0SP

On 7/11/2020 at 12:46 PM, mmang2758@... wrote:

Would like to get a discussion going on if it is necessary to use a Keying Relay Buffer when using the Palstar LA1K Amp. I called Palstar this week and talked with one of their technicians and told him I was planning on getting an LA1K amp in the near future.? I told him that I am using an Icom IC-7300. My question to the tech was do I need to use a Keying Buffer in between the LA1K and the IC-7300.
Palstar told me it wasn't necessary and that I just needed to use one RCA cable and connect it to the PTT connection. He also said to keep the transmit power on the exciter to 40 watts. Comments, suggestions greatly appreciated.

Mike.

I can agree with you Chuck that it is possible for the amp to be responding to antenna issues, and it would be great to know what they are so we can all fix them at our sites. That being said, I wonder if there is some commonality of our antennas. I am using a MyAntenna end fed long wire of about 125 feet. What are others using? I am especially curious if anyone is seeing this issue with a naturally resonant well tuned dipole configuration? Also I wonder why this event is coming back through my HF-AUTO? If I had the antenna connected directly to the amp (which I have tried and also fails) it would be more understandable. All we can do is keep investigating. I think my next step will be to try using my current wire at one of it's resonant points (based on my RigExpert 600), and then put up some form of simple dipole to test with.

Also of note - I had a nice call with my HRO technical support guy (who is great!!), and he has very good access to Palstar people. He did not get any silver bullets from Paul on this item, but he did get a commitment to have the web site updated with the latest version of the firmware when Mark gets back Wednesday (?), so we can all use the same version and eliminate any possible differences based on that. I think it is important to be using the current firmware whenever I am trying to resolve an issue.

I believe I have mentioned it before, but I am not doing CW, but rather one of the digital modes from fldigi. I have the levels set up so there is NO ALC indications on my rig ever, and I am providing about 5W of drive to get about 100W out of the amp. It will sometimes fail by just using the tune feature, which simply puts an audio tone out to trigger things like tuning? ;-} and it will fail on termination of the transmission. In the case of a real message it fails during the message after about 5 to 10 seconds most of the time.

_._,_._,_

-------- Original Message --------
Subject: Re: [la1k] Keying Relay Buffer Debate
From: "Chuck Scott" <cscott@...>
Date: Mon, July 13, 2020 4:25 pm
To: [email protected]

Al:

I was using my Mosley PRO67B beam for field day since I was running 1D due to being restricted in my travels this year for chemo treatment. The antenna normally works fine and I don't notice any issues with it or the feed lines. That said, I did run 100+ SSB contacts in some 40 minutes before I started to run out of steam. It was later in that run that some issues started to crop up.

Normally when I'm just casually chasing DX I use the HF-Auto App and let the tuner pick stored settings or go to bypass on it's own based on band, antenna, and frequency. I generally don't notice anything when I'm doing that. Not generating a lot of heat that way though. For field day I was running the tuner in bypass and staying on frequencies the antenna should be fine with.

My RF plumbing from the tuner goes through a power sensor for a MeterBuilder MB-1 (another piece of equipment that is pretty fast to detect SWR spikes) and when I did take a look at it I was seeing some odd spikes there at times, which again indicates there was something going on outside of the Palstar equipment. After that it goes through my ground panel and protector, then a run up to the top of the tower and finally a short ultra-flex jumper to the antenna. When I changed it to go straight from the amp to the line coming from the tower without the tuner I of course saw less indication of a problem till the amp tripped.

So I would have to say that in my case there must be an issue with cables or connectors of so sort. The cable is all LMR-400 or LMR-400 UltraFlex. Those all had standard solder/clamp connectors (as I mentioned) and I've since become less than convinced of their reliability. Since moving most things to solder (center pin) / crimp (shield) there seems to be better reliability, but the cabling to the PRO67B beam hasn't been upgraded for that yet.? If things go well with chemo this time around I'll probably do that this fall.

Having said all of that, the symptoms at the HF-AUTO and LA-1K are still similar to those that have otherwise been reported except that I have other equipment giving me a bit more information, like the MB-1. In other words, I know something is going on, but it's so fast that I don't generally see it at the amp when it trips. What kinds of things that might show this kind of fast SWR spike on the transmission lines and antennas is probably a good thing for discussion and I'm sure there's quite a list of possibilities.

I also do have a folded dipole I use, but I run that at lower power and don't think I've ever seen any such issues using that.

One comment about "end fed long wire" antennas. First of there isn't really such a thing as an "end-fed" antenna when you get down to it. Most of the time the end-fed is really balanced against transmission line, a ground stake, or counterpoise wire, or some such thing. However, there can be some really high Z points where things might be supported at certain frequencies, particularly if it's running as a 1/2 wave. At that point, high voltage discharges might not be a surprise.

Chuck - N8DNX

On 7/13/2020 3:51 PM, Al Womelsdorf via wrote:

I can agree with you Chuck that it is possible for the amp to be responding to antenna issues, and it would be great to know what they are so we can all fix them at our sites. That being said, I wonder if there is some commonality of our antennas. I am using a MyAntenna end fed long wire of about 125 feet. What are others using? I am especially curious if anyone is seeing this issue with a naturally resonant well tuned dipole configuration? Also I wonder why this event is coming back through my HF-AUTO? If I had the antenna connected directly to the amp (which I have tried and also fails) it would be more understandable. All we can do is keep investigating. I think my next step will be to try using my current wire at one of it's resonant points (based on my RigExpert 600), and then put up some form of simple dipole to test with.

Also of note - I had a nice call with my HRO technical support guy (who is great!!), and he has very good access to Palstar people. He did not get any silver bullets from Paul on this item, but he did get a commitment to have the web site updated with the latest version of the firmware when Mark gets back Wednesday (?), so we can all use the same version and eliminate any possible differences based on that. I think it is important to be using the current firmware whenever I am trying to resolve an issue.

I believe I have mentioned it before, but I am not doing CW, but rather one of the digital modes from fldigi. I have the levels set up so there is NO ALC indications on my rig ever, and I am providing about 5W of drive to get about 100W out of the amp. It will sometimes fail by just using the tune feature, which simply puts an audio tone out to trigger things like tuning? ;-} and it will fail on termination of the transmission. In the case of a real message it fails during the message after about 5 to 10 seconds most of the time.

What are you using as a protector? ?A month or so ago the group found that PolyPhaser arrestors have issues with SWR spikes that Alpha Delta arrestors dont.