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Author Topic: RM Italy BLA 350 -- Overpriced????  (Read 31091 times)
K4RVN
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Posts: 758




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« Reply #60 on: February 16, 2014, 01:20:21 PM »

 Answering the original post topic , this amp is advertised at 600 watts PEP SSB which from a watts per dollar is reasonable price  due to the poor regard for our dollar value  as others have pointed out. Since it is new on the market, it has no proven performance track record in this country that I am aware of as I have never heard one on the air.
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K4RVN
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Posts: 758




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« Reply #61 on: February 16, 2014, 09:23:05 PM »

I saw a test on this amp on the internet via u tube using 7 watts drive produced under 500 watts peak. Turning the drive up to 10 watts was not clean at 500 plus watts peak. So please disregard my comments about it being a good watt for the dollar price as I should have waited for more info. It looked good at reduced power of slightly over 300 watts according to the conversation on
u tube.

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KD4TWP
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Posts: 28




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« Reply #62 on: March 05, 2014, 07:42:42 AM »

At last! somebody gets the whole idea. people bitch and moan about Cb this Ham that! get over it and enjoy the hobby. The subject is about price. Not politics.
 Bottom line is ive been saving money for a year to buy a  solid state no tune amp to use with my QRP Base. and all I have is $750 bucks and that's all I have and not getting any more anytime soon and not waiting any more. what do I do? go buy a used "ham" amp? or buy the new BLA-350?
Ive seen all the reviews on the BLA and what I gather is if you don't over drive it it is a great amp, and already know all about the Ham amps. and the cheapest one I can find is the AL-811 $730.00 from DX emerging. And the BLA-350 for $750.00 from HY electronics.
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K6AER
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Posts: 3488




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« Reply #63 on: March 05, 2014, 09:14:32 AM »

In the bang for the buck category for QRP operation consider the RM-300 HV (250 Watts PEP)or the ALS-500 (370 watts PEP) used. Run them at 14.4 VDC and don't overdrive them.
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ZENKI
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Posts: 906




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« Reply #64 on: March 06, 2014, 02:52:32 AM »

Yeah smart hams and even engineers can drive these crap CB amplifiers to improve  their IMD performance. They must have the engineering skills of  the gods.

Boys and girls buy your CB amps, you are very smart CB engineers ... you  so skilled, you can adjust them thar knobs to put out a clean signal from a CB amp with marginal IMD performance. Your marginally filthy ham radio driving a crap CB amplifier will be clean because  your smart fingers can set those  to the clean setting. Your CB golden intelligent fingers  can do the tuning for you. Why do you do a clean ham transmitter and amplifier, Mr CB golden fingers  can clean tune your bitter pill box for a clean signal.

Now we have on display the  CB engineering intellect that is permeating the ham service.

Hams seem to be getting dumb  and the stupid technical arguments that justifies polluting the ham bands  seem to be getting worst.

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M0HCN
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Posts: 473




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« Reply #65 on: March 08, 2014, 11:34:30 AM »

Not the engineering skills of the gods, but adaptive predistortion has been recently demonstrated to get better then -40dBc IM3 from a mosfet stage biased rather more class B then AB, 100mA @50V rather then 1A (-40dBc is least as good as many of the rigs out there :-( ).

Some discussion on the HPSDR list in the last day or so, it would be very interesting to see what would happen if you put one of these cheap amps inside that kind of feedback loop.
I doubt it would make the -60dBc of a good 50V LDMOS stage in such a loop, but it might well make -40dBc or so, which would be good enough to not be a total embarrassment.

I am holding out for full on cartesian loop, but have to admit that the adaptive predistortion loops are putting in a good showing with a range of different power stages.

Of course doing this does sort of imply a fairly serious SDR of the DDC/DUC variety to be able to close the loop with sufficient accuracy.

73 Dan.
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WD5GWY
Member

Posts: 391




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« Reply #66 on: March 08, 2014, 03:15:47 PM »

No expert on the subject, but, I would think that Adaptive Predistortion would have no
effect on amps like the RM Italy's being discussed here.
RM Italy amps are not known at all for clean output. Lowering the drive in an attempt to
obtain a clean output is a waste of time. Without proper design to begin with, it will have
no effect at all. (might lower the signal strength of the spurs etc. that the amp produces,
but it won't eliminate them)
   KD4TWP, if you've got $750 to spend on an amp, you can pick up a nice 811h used
for less than that. And there are other amps that can be purchased used in a similar
price range. Oh, you are right the subject is not about politics, as you said, it's about price.
BUT, as so many have tried to point out, it is about cleaning up our ham bands as well.
Using poorly designed equipment to "enjoy the hobby" without consideration to other amateurs,
is simply rude. It is not that hard to find decent radios and amps that do not trash the bands
with unnecessary splatter.
  Unfortunately, it has become a ME world and a lot of people, (but thankfully, not all) do not
care how they effect others around them. (which is becoming true in more aspects of life and
is not limited to Amateur Radio)
   james
WD5GWY
 
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G3RZP
Member

Posts: 4393




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« Reply #67 on: March 08, 2014, 11:13:30 PM »

After the last generation of transceivers with tube PA stages, the high order IMD (and the lower order for that matter) significantly degraded, with the exception of those Yaesu transceivers that had the Class A PA option. I covered this in my lecture at last year's RSGB Convention, entitled 'Spreading the Sewage' (More polite than 'Slinging the S***!). I don't have the capability of putting the slides up on the web, though.
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WD5GWY
Member

Posts: 391




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« Reply #68 on: March 09, 2014, 11:55:19 AM »

After the last generation of transceivers with tube PA stages, the high order IMD (and the lower order for that matter) significantly degraded, with the exception of those Yaesu transceivers that had the Class A PA option. I covered this in my lecture at last year's RSGB Convention, entitled 'Spreading the Sewage' (More polite than 'Slinging the S***!). I don't have the capability of putting the slides up on the web, though.
Too bad, I would like to see the slides. Do you think you could post the lecture itself? Even without the slides, it might help open some eyes. (then again, maybe not) It does look like there are some
manufacturers and software developers making some efforts to provide equipment with cleaner signals. Hopefully, one day others will follow their lead. But, like Zinki, I kind of doubt it, as Amateurs are not a big market to them and we don't seem to care enough to push them towards
better equipment.
james
WD5GWY
 
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