[Amps] SPE 1.3K-FA and FTDX-5KMP

Tue Nov 17 02:16:03 EST 2015

VE7RF, I live and xmit in Thailand.  
I see you, Jim, do not fathom the concept... I DO NOT CARE.
My concern is to be heard, comply with local emissions rules, and relax.
I still recommend you go visit people in nursing home or equiv. and smilingly and in a jovial way, tell them about IMD.  They could possibly care more than me, but ..........
73, Charly

From: jim.thom at telus.net
To: k4vud at hotmail.com; amps at contesting.com
Subject: Re: [Amps] SPE 1.3K-FA and FTDX-5KMP
Date: Mon, 16 Nov 2015 17:24:23 -0800

###  Charly,  you still don’t fathom the concept of bad TX  
IMD...on  SSB !     You can have the very best RCVR on 
the planet, and it will  do you NO good at all, if the bozo
above / below your freq....is transmitting wideband  IMD 
garbage.   If you have a 2nd  spare XCVR..... put in on your 
desk, with perhaps a 2-6 inch piece of wire stuffed into the
SO-239  for a temp antenna.    Switch in some RX  
attenuation on the 2nd  XCVR.    Then  TX on your main 
xcvr...with and without the SPE amp...and listen with headphones on the
temp 2nd xcvr.    Then tune  up /down  on the 2nd 
xcvr...listening for IMD crap.    Also try switching in any 
speech processing..and u will see that the imd crap gets a helluva lot 
louder
still.    These days,  you wont make any friends with a 
lousy TX signal.    SPE is delusional if they think they are 
building state of the art amps.  

Jim   VE7RF

From: Charles H 
Sent: Monday, November 16, 2015 4:00 PM
To: Jim 
Thomson ; amps at contesting.com 
Subject: RE: [Amps] SPE 1.3K-FA and FTDX-5KMP

Leigh, with all the great rcvrs out there, I do not worry about my 
transmitted signal.   Whenever a ham has the urge to write or even 
worry about IMD, he should instead go visit a shut-in or a nursing home and 
cheer people up.  73, Charly

> From: jim.thom at telus.net
> To: amps at contesting.com
> Date: 
Mon, 16 Nov 2015 02:49:29 -0800
> Subject: [Amps] SPE 1.3K-FA and 
FTDX-5KMP
> 
> Date: Sat, 14 Nov 2015 08:28:13 +1030
> From: 
"Leigh Turner" <invertech at frontierisp.net.au>
> To: 
<amps at contesting.com>
> Subject: Re: [Amps] SPE 1.3K-FA and 
FTDX-5KMP
> 
> 
> Charly, sadly there's an over-hyped 
obsession out there about Tx purity and
> associated IMD specs for ham 
rigs....
> 
> Having said that many current SS amp offerings are 
poor performers in this
> regard when driven to their rated PEP output 
:-(
> 
> Leigh
> VK5KLT
> 
> ### Leigh, the yaesu 
FTDX-5000MP uses a PAIR of VRF-1511Gs. They are the
> 170 vdc rated 
version of the MRF-151G..... ( 50-60 vdc rated). 
> 
> ## Now comes 
along SPE..with its 2.0K...running a whopping 2 kw pep output from
> just 
SIX MRF-151Gs. Now if SPE can achieve 2000w pep from 6 x devices, then
> 
yaesu should be able to get 666 watts pep from 2 x devices. Can you imagine 
the
> FTDX-5K running 666 w pep out ? Well it would fare a little better 
than the SPE junk.
> 
> ## at least yaesu, and also the SS in the 
ARRL handbook, both used VRF-151Gs. 
> SPE didn’t even use the correct 
version of the 151G. The SS devices usually fare a 
> lot better with 
higher voltages, with reduced imd being the result. If folks want to 
> 
run high power on ssb, then at least take advantage in the latest and greatest 
in
> technology..and use the 170 vdc rated VRF-151G. doesn’t cost anymore 

> than the MRF-151G. The VRF-151G has been out for several years 
now...
> its old news really. Perhaps SPE didn’t get the memo ? 
> 

> ## Like I mentioned b4, that SPE 6 x MRF-151G amp is a 600-750 watt 
pep
> output max amp on ssb, that’s it. 2000w pep out from it would be 4 
steps
> below an imd garage truck. And no, the FCC etc, don’t regulate 
crap IMD
> on the ham bands. No specs, no regulations pertaining to IMD, 
be as wide
> as you want, as long as its within the ham bands etc. 

> 
> ## yaesu in class A..... driving any of the 3 x spe amps... to 
rated output =
> IMD garbage. But folks like charly say they only look at 
one spec... rated pep
> out on ssb. 
> 
> ## BTW, if you look 
through the online SPE manuals, they say not to use speech processing,
> 
since this increases the duty cycle on the ss amp..and it will cook. (it will 
also increase the average power in the
> imd products, so the imd will 
then sound even louder). 
> 
> ## No folks, SPE didn’t get it right. 
They are selling you a bill of goods. End of story.
> 
> Jim 
VE7RF
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