[Amps] SPE 1.3K-FA and FTDX-5KMP
k4vud at hotmail.com
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 ..........
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
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.
From: Charles H
Sent: Monday, November 16, 2015 4:00 PM
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
Mon, 16 Nov 2015 02:49:29 -0800
> Subject: [Amps] SPE 1.3K-FA and
> Date: Sat, 14 Nov 2015 08:28:13 +1030
"Leigh Turner" <invertech at frontierisp.net.au>
<amps at contesting.com>
> Subject: Re: [Amps] SPE 1.3K-FA and
> Charly, sadly there's an over-hyped
obsession out there about Tx purity and
> associated IMD specs for ham
> Having said that many current SS amp offerings are
poor performers in this
> regard when driven to their rated PEP output
> ### 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
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
> 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
> 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
> 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
> output max amp on ssb, that’s it. 2000w pep out from it would be 4
> below an imd garage truck. And no, the FCC etc, don’t regulate
> 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.
> Amps at contesting.com
More information about the Amps