Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: Prev 1 [2]   Go Down
  Print  
Author Topic: FT 101 E Peak Envelope Power MFJ 948 Tuner  (Read 4004 times)
N1UK
Member

Posts: 1408




Ignore
« Reply #15 on: August 26, 2007, 07:22:27 AM »

Yes I was confusing the two . Thank you for putting me straight on that one. How accurate is the MFJ at reading PEP?

Mark N1UK G3ZZM
Logged
K7KBN
Member

Posts: 2785




Ignore
« Reply #16 on: August 28, 2007, 10:11:38 AM »

It agrees pretty closely with PEP meters from other manufacturers.  Probably within plus/minus five to ten percent of the "true" reading.  
Logged

73
Pat K7KBN
CWO4 USNR Ret.
WB2WIK
Member

Posts: 20567




Ignore
« Reply #17 on: August 28, 2007, 01:18:24 PM »

Don't confuse PEP and peak?  What are you talking about?

To measure PEP power, of course active, powered circuitry is absolutely required.  What would bias the peak sample and hold circuit?  It can't be powered by RF or by magic.

There's no definition or usage of "peak" power in the world of voice modulated radio transmitters, at all.  PEP is the only term used and defined.  The ITU regulates this worldwide, and they only define power three ways: None of those are "peak."

A pretty good writeup on this is here:

http://www.vk1od.net/VSWR/MeasureSSBTxPower.htm

WB2WIK/6
Logged
K7KBN
Member

Posts: 2785




Ignore
« Reply #18 on: September 04, 2007, 05:23:16 PM »

Steve - I think the folks at Bird know what they're talking about.  Their Model 43, as I know you know, measures CW power (which is the same thing as PEP, for all practical purposes - or so I have been trained to believe).  It has NO internal batteries or external power supply of any sort, for any purpose.

The Model 43P DOES require batteries or external power for operating the Peak (not PEP) reading circuitry.

Whether such instrumentation as Peak RF Wattmeters is necessary (and maybe it's not, judging from your last post) is not for me to determine.  However, if as respected an authority in the field as Bird chooses to design, manufacture and sell such instrumentation, I'd imagine they have a good reason.

I used to work in a Navy calibration lab, and one of the types of instruments I'd receive for calibration and/or repair were Birds and their associated slugs.  At that time, each Bird 43 HAD to be calibrated with slugs identifiable by serial number, and woe to the technician on the waterfront who used a slug that wasn't on the list for a particular Bird 43!
Logged

73
Pat K7KBN
CWO4 USNR Ret.
WB2WIK
Member

Posts: 20567




Ignore
« Reply #19 on: September 05, 2007, 10:43:05 AM »

>RE: FT 101 E Peak Envelope Power MFJ 948 Tuner  Reply  
by K7KBN on September 4, 2007  Mail this to a friend!  
Steve - I think the folks at Bird know what they're talking about.<

::Yes, they do.  I wrote some of their marketing collateral for them back in 1969.

>Their Model 43, as I know you know, measures CW power (which is the same thing as PEP, for all practical purposes - or so I have been trained to believe).<

::Nope, your training is very wrong.  CW and PEP are the same power when using CW, which is a continuous wave mode, providing the CW signal isn't interrupted by keying to add communications intelligence.  FM and PEP would also be the same, and for the same reason; no amplitude modulation.  As soon as you go to any AM mode including SSB, there are huge differences in measurement requirements and a Bird 43 cannot measure PEP at all, unless the operating mode is CW or FM where there is no amplitude modulation.  Bird 43 cannot measure PEP for AM, for SSB, for pulse modulation...

>It has NO internal batteries or external power supply of any sort, for any purpose.<

::That's true, it doesn't need any since a CW signal is continuous wave.  A keyed CW signal (A1A) is an interrupted continuous wave.  If you send dits and dahs when using a Bird 43 to measure power, you'll see it indicates *WAY* less power than if you just close the key continuously and send a carrier.  That's because it can't measure PEP.  If you use a Bird 43P (the PEP version of the same meter), you'll see the continuous carrier or the dits-and-dahs sending will both read the same power.

>The Model 43P DOES require batteries or external power for operating the Peak (not PEP) reading circuitry.<

::The 43P is a "PEP" reading meter, by definition.  Again, no matter what anyone calls it, there are only a few ways to indicate power according to the I.T.U., which regulates all transmitters everywhere in the world including here.  PEP is one of them.  "Peak" is not one of them.

>Whether such instrumentation as Peak RF Wattmeters is necessary (and maybe it's not, judging from your last post) is not for me to determine. However, if as respected an authority in the field as Bird chooses to design, manufacture and sell such instrumentation, I'd imagine they have a good reason.<

::Well, sure they do.  A Bird 43 and many other instruments are very useful for measuring the output power of FM transmitters, for example: No amplitude modulaton means an FM signal is the same as an uninterrupted CW signal.  It's CW power.  Bird 43s can also be used to measure the carrier output power of an AM transmitter, as long as you're only interested in measuring carrier power.  It can't measure the PEP power of an AM transmitter, which is the only thing amateur radio operators should be concerned with, since we are regulated by PEP power and not carrier power in Part 97.

-WB2WIK/6
Logged
K7KBN
Member

Posts: 2785




Ignore
« Reply #20 on: September 05, 2007, 03:44:01 PM »

Okay.  Just to point out, however, that the Bird 43/43P operating manual - at least the one online - makes no mention whatsoever of "PEP", and refers to the 43P as a "PEAK" reading instrument.  Perhaps you should correct them.
Logged

73
Pat K7KBN
CWO4 USNR Ret.
WB2WIK
Member

Posts: 20567




Ignore
« Reply #21 on: September 07, 2007, 11:14:05 AM »

KBN: What you say doesn't seem to be true (far as I can tell).

The model 43P was discontinued and replaced with this one, which does have its data sheet and manual on line and they do refer to it as a "PEP" wattmeter as follows (cut and pasted from Bird Electronic website five minutes ago):

>4314B Thruline® Wattmeter
 PEP, Single element, Portable Wattmeter
 Accurate CW and Peak Envelope (PEP) field power measurement over 450 kHz to 2.7 GHz and 100 mW to 10 KW.
Uses industry standard Bird elements with space to store 2 additional within the meter housing.
Rugged metal housing for the most demanding environments.
Quick Change (QC) connectors to minimize the need for adaptors when making critical measurements.
 
 
 The Bird 4314B Wattmeter is similar to the Bird Model 43 Thruline Wattmeter but also contains electronic circuitry to accurately measure peak envelope power which is present in amplitude modulated signals such as AM broadcast, single sideband and TV video transmitters. The circuitry operates from 2 standard 9V alkaline batteries or an optional A.C. adaptor.<

They have no listing whatever for the 43P that I could find.  And this one, the 4314B, appears identical to the 43P's that I own, I don't see any difference except the model number.

And they DO call it a "PEP" meter.  

WB2WIK/6
 
Logged
2E0BSS
Member

Posts: 85




Ignore
« Reply #22 on: September 07, 2007, 11:31:00 AM »

Great information folks. I'm in the process of having the unit serviced by an expert (someone who knows these things and fixes them professionally) upto now the set isn't doing to well it's off transmitting frequency by 6.75kc's and it's receive frequency isn't much better either ok that's only out by a variable 3-6 depends on the frequency used.

As for RF power well that's not too good either it will push 90watts this drops off after a few seconds and if continually used it goes to around 10 watts.

I'm having the set serviced because it's what I consider amatuer radio (seeing a set like that some 30 years ago gave me the radio bug)I'm not a fan of all these new base stations which glow all pretty colours plus the FT101E's sound is better than the lot oh that was one thing the engineers first report said was ok the receiver is working all be it off frequency.


I'm now looking for the service equipment myself so I can get a dead radio and try to fix it any advise on finding the individual units would be great.


Charlotte 2E0BSS

Logged
K7KBN
Member

Posts: 2785




Ignore
« Reply #23 on: September 08, 2007, 08:09:39 AM »

http://www.repeater-builder.com/other-mfrs/bird-43-wattmeter-2001.pdf
Logged

73
Pat K7KBN
CWO4 USNR Ret.
WB2WIK
Member

Posts: 20567




Ignore
« Reply #24 on: September 09, 2007, 11:59:00 AM »

K7KBN, that's a six year-old reference on a "ham" independent web site; it's not Bird's website, and if you look at Bird's website you'll see the 43P is indeed discontinued and replaced by the 4310 which is listed as a "PEP" wattmeter.

Bird discovered their mistake (using the term "peak" instead of PEP, since there is no definition of peak power in international regulations) and changed it in 2004.

WB2WIK/6
Logged
K7KBN
Member

Posts: 2785




Ignore
« Reply #25 on: September 09, 2007, 02:27:45 PM »

Thanks, Steve.
Logged

73
Pat K7KBN
CWO4 USNR Ret.
K7KBN
Member

Posts: 2785




Ignore
« Reply #26 on: September 09, 2007, 02:28:04 PM »

Thanks, Steve.
Logged

73
Pat K7KBN
CWO4 USNR Ret.
Pages: Prev 1 [2]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!