CQ-Contest
[Top] [All Lists]

Re: [CQ-Contest] PGXL in SO2R mode? (RIP K7BV)

To: cq-contest@contesting.com
Subject: Re: [CQ-Contest] PGXL in SO2R mode? (RIP K7BV)
From: Jeff Blaine <KeepWalking188@ac0c.com>
Date: Mon, 13 Jan 2025 19:14:30 -0600
List-post: <mailto:cq-contest@contesting.com>
Mike,

I have the PGXL here setup in SO2r.  It's run a bunch of RTTY contests and has been beat severely but keeps rocking along.  K9CT suggested the amp to me based on his description of running one in this same situation (So2r RTTY) and I thought it was nonsense. But having had the amp for years now, he's right - the thing is indestructible for the most part.

There are two in and two outputs on the PGXL - one for each rig. I don't think there is an antenna switch function between out A and out B as far as I know - it's just rig A in --> rig A out. In my context, all the antenna switching is done after the amp anyway by a seperate uHam SMD system to drive all the back end stuff - and that also handles the PTT timing stuff.

I've run it with a pair of Yaesu 5K and then more recently, a pair of FTdx101mp.  No overshoot issue that I've seen - and the PGXL is pretty self-protecting if you hammer it with a full 100-200W (which I have done many, many, may times).

Regarding the PTT timing, later versions of the flex firmware have implemented an early RF detection system of some kind which in my case never did work right.  The fix was just to use the firmware version prior to this "feature" implementation and it's been perfect with that.  This is a minor nit but if you use a non-Flex rig with it, and load up the latest firmware, you may or may not see this and spend a day tracing ghosts that turn out to be phantoms rather than timing problems.

In a contesting sense, if you had an overshoot issue at reduced power, I would just use a 2-3 dB fixed pad inline with the rig. The attenuation on RX would be insignificant and the TX could run at full power.   I don't have an Icom here in the shack but do have a bunch of old gear that has pretty severe overshoot on the initial CW element and have a fixed pad system for that purpose and it pretty well settles all the TX issues.

If this one exploded today, I would have no problems buying another one to replace it.  I don't have any other Flex gear in the shack - but the PGXL is just served me well and with the So2r capability and the fact I've not managed to blow it up in RTTY contest service has me a PGXL fanboy here.

73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com

On 1/13/2025 1:37 PM, Mike Smith VE9AA wrote:
(K7BV(sk) content at the bottom of this message)

Anyone here using a PGXL as their only SO2R amplifier?

I have what I think are a couple of fairly unique questions I can't find
answers to via Google or the user manual.

IE: I run a pair of IC-7410 Icoms (currently, someday I'll upgrade, probably
to original K3's(non-S's)) and these 7410's are known to have a small amount
of initial overshoot. How bad, I don't know. It's no longer fixable by Icom.
(related) : TX delay is NOT adjustable like in most modern transceivers.(I
use N1MM&YCCC SO2R+ to do the TX delay)?

Second question.  Is it possible to connect radio "A"  to an antenna switch
to feed 6 various antennas, but radio "B" only gets a single antenna or is
there any kind of funny antenna swapping done inside the PGXL like another
popular SS amplifier which won't work for me because of this quirky feature?


SO2R is not really discussed in the manual.  I am not clear on how the
radio(s) and the PGXL would share the same com port, say to N1MMLogger+ for
example?

They're a lot of money to a Canadian, so I want to be sure before I finish
saving up $$ and purchase one, it's what will work here, otherwise, I'll
just stick to a pair of smaller amps for the time being.

Thanks to all you "contesting piggies" and before I sign off...RIP Dennis,
K7BV(sk).  We'll miss you.

K7BV, VE1PZ and VE9AA were CY9AA 1997 https://www.uksmg.org/content/cy9.htm
if you want to read Dennis' writeup of the experience. He was a great member
of our little team and ran endless pileups seemingly fueled by Island coffee
alone....btw I found Dennis' on this very reflector in 1997 and what a great
choice he was. Dude, I hope you're running pileups up there right now.<sk>

Mike VE9AA - Keswick Ridge, NB, Canada




_______________________________________________
CQ-Contest mailing list
CQ-Contest@contesting.com
http://lists.contesting.com/mailman/listinfo/cq-contest
_______________________________________________
CQ-Contest mailing list
CQ-Contest@contesting.com
http://lists.contesting.com/mailman/listinfo/cq-contest
<Prev in Thread] Current Thread [Next in Thread>