Since nobody believes a 148/grant will do 25+ watts...

[Moleculo]

This whole thing started when someone claimed absurd AVERAGE or RMS numbers. Show a video of what that does on a Bird 43 with a 50 watt element.

I can't tell you what his Radio Shack meter reads. I found one that I had sitting in a drawer when I did this video and put it on for kicks. It didn't seem to matter what radio I put it on, it kept reading the same thing. So I guess THAT's going in the trash pile. Maybe I'll test it to see if still works as an SWR meter. Perhaps

Anyway, read up a few posts. I mentioned that the radio reads 9 watts on the Bird 43 in AVG mode. That's from a 2 watt resting carrier (deadkey).

 

[C2]

how much of those 25W is channel power, ACP, or in the 2nd and 3rd harmonic?

 

[davegrantsr]

i don't have the time to delve into the 22 watt rating of 2sc1969's & what happens to them when they get hammered. we know what happens to 2sc2879's when they exceed their 120 watt rating-sometimes good, sometimes bad. the same applies to the lil ole 1969.-i was 'implying', C2, but since you were so straightforward in asking....i am, however, afraid to hear the answer, because... :roll:

 

[Toll_Free]

Looks like someone cleaned up the other thread...

Since a bunch of people claimed BS on the assertion that a 148/Grant can do 25+ watts, I took my own personal Grant LT that has the same mods that I did to Nightrider's, put it on my bench and shot a video. There's no tricks here folks...it's just a quick and dirty (slightly out of focus) clip from my digital camera. The watt meter is a Bird43P. You can see for yourself the voltage reading from the power supply. This clip is showing the power reading on AM with a 50 watt slug. You're also hearing audio that is feeding back from an Yaesu 857D that is on the bench, which I use to monitor (among other things).

http://forum.worldwidedx.com/images/grant.wmv

This whole thing started when someone claimed absurd AVERAGE or RMS numbers. Show a video of what that does on a Bird 43 with a 50 watt element.

Using a 50 watt element to measure a 25 watt radio is stupid.

Bird and Coax Dynamics only rate the accuracy of their meters at full scale. I can make a Bird read whatever I want mid scale, depending on the filthiness of the exciter.

Yet another post proving ignorance.


--Toll_Free

 

[psycho]

This whole thing started when someone claimed absurd AVERAGE or RMS numbers. Show a video of what that does on a Bird 43 with a 50 watt element.

I can't tell you what his Radio Shack meter reads. I found one that I had sitting in a drawer when I did this video and put it on for kicks. It didn't seem to matter what radio I put it on, it kept reading the same thing. So I guess THAT's going in the trash pile. Maybe I'll test it to see if still works as an SWR meter. Perhaps

Anyway, read up a few posts. I mentioned that the radio reads 9 watts on the Bird 43 in AVG mode. That's from a 2 watt resting carrier (deadkey).

2 watts swing to 9 watts on a Bird 43 is excellent. My General Lee swings to 12 watts from 1/2 a watt and that has 2 1969s.

 

[psycho]

Looks like someone cleaned up the other thread...

Since a bunch of people claimed BS on the assertion that a 148/Grant can do 25+ watts, I took my own personal Grant LT that has the same mods that I did to Nightrider's, put it on my bench and shot a video. There's no tricks here folks...it's just a quick and dirty (slightly out of focus) clip from my digital camera. The watt meter is a Bird43P. You can see for yourself the voltage reading from the power supply. This clip is showing the power reading on AM with a 50 watt slug. You're also hearing audio that is feeding back from an Yaesu 857D that is on the bench, which I use to monitor (among other things).

http://forum.worldwidedx.com/images/grant.wmv

This whole thing started when someone claimed absurd AVERAGE or RMS numbers. Show a video of what that does on a Bird 43 with a 50 watt element.

Using a 50 watt element to measure a 25 watt radio is stupid.

Bird and Coax Dynamics only rate the accuracy of their meters at full scale. I can make a Bird read whatever I want mid scale, depending on the filthiness of the exciter.

Yet another post proving ignorance.


--Toll_Free

I'm glad you have such respect and faith in Bird products to say at mid scale they are useless. Bird meters read heat and could care less about "filthiness".

Your ignorance has made an appearance. :shock:

 

[Moleculo]

I understand what you're saying Toll Free, but when it does more than 25, and less than 50, what are you supposed to do...Order a custom made slug? That doesn't sound very realistic to me. I suppose you could use something else to measure it besides a bird meter, but when that's what you got...

Regarding your question C2, I can't answer that exactly because I don't have a spec analyzer. However, because part of the modifications involve bias stabilization (especially on the neg peaks) I would assume that would help linearity.

If you have a Spec Analyzer, send me a 148/Grant and I'll do the mods for you and send it back....just pay the shipping. You can put it on your Spec Analyzer for us all to see.

 

[bob85]

hey mole does the stabilising bias audibly improve the sound of ssb at all??

 

[C2]

Sorry Molecular dude. I don't have a 148. But if I did, that would only prove what "my" 148 could do.

What comes to mind is a post that Lazy wrote about, something about a LP filter on his splatterbox?

psycho is right, "Bird meters...could care less about "filthiness""

Maybe freecell could tell us if they read heat or not

 

[Moleculo]

I didn't mess with any of the output filtering in the radio. I also didn't have a reason to mess with the band pass filter since this radio didn't have extra frequencies added. The final wasn't volted, and the modulation was adjusted as carefully as I could do it using my scope and tone generator. I can't see how the power

Bob85, I would assume that the SSB linearity would be improved by stabilizing the bias. Anyway, Justin outlined this mod already on the forum for all to see, and he gave explanations. The post is here:

http://forum.worldwidedx.com/viewtopic.php?t=15314

I have a few additional notes / clarifications. Also, he told me that the results work well also without replacing the AM regulator (I've done that a few times as well). Anyway, one thing Justin is not known for is putting out mods or work that causes unnecessary distortion or IMD (in fact he's one of the biggest critic of mods like that), so I don't have a problem doing this mod. If someone wants to perform it an prove otherwise, then great....we'll all learn something. Until then your speculation is just....well speculation.

 

[Geekster]

None of it means squat if you do not have the NIST (MIL-STD-45662A, ANSI/NCSL Z540-1-1994 or equivalent) paperwork.

Sorry, but if we are slicing hairs we need some standards here.
As You Were

 

[C2]

I know that is the image that J wanted to project, but I read his post here where he tore into the subject and admitted that he had to do what he had to do.

I think I remember the video of the 50W cobra 29 or whatever it was putting out on the spec an. I addressed the issues there as well and there was no defense.

How about this, I can characterize anyone's radio with the following equipment:

Tek 2430A scope
Tek 496 Spec An.
HP 8901B Modulation Analyzer

I'll also do the receiver sensitivity SINAD measurement.

 

[KingCobra_CDX882]

Hey ?

Those are AB-1 Biased wattage right :lol :lol

 

[Toll_Free]

I'm glad you have such respect and faith in Bird products to say at mid scale they are useless. Bird meters read heat and could care less about "filthiness".

Your ignorance has made an appearance. :shock:

lol. I love it when people think they know what they are talking about, when in actuality, they make themselves look more and more <<stupid>> with every post they make.

Bird makes many things, Einstein. Terminations, Wattmeters, line sections and calorimeters, to name a few.

Bird rates their 43 ONLY at full scale. THEY rate the accuracy suspect UP TO 25 percent of mid scale. THEY will tell you to pick an element that is towards the middle or upper part of the scale. I've dealt with Bird Electronics, Altronics, Coax Dynamics for years, and know what they can, and can't do. These notes pertain to the 43 series of wattmeters. A VOLTAGE BASED DEVICE.

A CALORIMETER measures heat. It is a combination termination and temperature probe. They either provide a nomograph to computer Pout by measuring ambient (room) temperature and the heated product (either ethelyne glycol for HUGE loads, or distilled water for most stuff). The temp diff gives you Pout.

A voltmeter based device (the Bird 43) is a voltmeter. Take a slug apart. It is a loosely coupled device, terminated with a finite resistance on one end and a meter and rectification circuit at the other end.

The digital meters are a different animal, and cost appropriately. If you would like, someday, I'll break one out when you're on the West Side. My friggin wattmeter costs more than your car, Jr. I got lucky and purchased one from a friend who got lucky and so on and so forth. Most of the "smart" people on rec.radio.cb picked one up almost a decade ago. The meters where > 10 thousand dollars then.

Now, as far as filthiness goes, all meters measure filth. Especially the Bird. If you don't believe me, do a simple check.

Take a stock 29 and texas star 350 and measure the output into a dummy load.

remove the limiter and measure the new output.

remove ONE parasitic inside the 350 and measure the output... WHOOPS, it breaks into oscillation and you see BIG numbers. I can MAKE a 350 read > 1,000 watts, PEP, Bird 43.

Bird Electronics will back up any and all claims I've made. You're welcome to go to their site and check it for yourself.... Or, go check Coaxial Dynamics website.. They are ex Bird Engineers who bailed and formed their own company.

Bontoon also markets a Bird compatible product, but I doubt a moron like you ever heard of them.

--Toll_Free

 

[ken white]

If the metering circuit is a moving needle analog type, which the Bird 43 is, then the meter is typically most accurate towards the low end near mid-scale. When an analog meter movement moves towards the high end, the coils tend to saturate and the springs become non-linear. This is why the scale is typically graduated in a non linear fashion on the meter movement.

The Bird 43 is rated at +/- 5% of the FS (Full Scale) which means for a 50W slug, the maximum error will be no more than +/- 2.5W no matter what value is measured. So as a % of measured error, FS will be most accuate by specification, but least accurate by meter movement since a small change in the needle near FS means a big difference in the reading.

I have always tried to use mid-scale for my measurements when using an analog meter. Just my $0.02...

Oh, and like Toll_Free said, the slug is just a rectifier and averaging circuit that produces a voltage out proportional to power. The BW of the circuit is pretty wide, so splatter is measured equally well too, and the meter does not measure heat or true power.