Subject: Veronica V.S. Ramsey Tractor pull! Sunday Sunday Sunday
From: xxxxx@hpessxw.fc.hp.com (Glen Coyote Water and Pow
er)
Date: 1997/06/10
Message-ID: <5nkaef$fs0@fcnews.fc.hp.com>
Newsgroups: alt.radio.pirate
OK, since I own both kits, let's compare:
Disclaimer: Let's just say, "In my opinion.... "
1W _PLL_ _Veronica_ w/stereo coder and 2 limiters | Ramsey FM100 EX
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Function:
FM Stereo transmitter for FM BC band | same
Advertised RF power:
A little less than 1 watt into a 50 load | same (also 75 ohm load)
Frequency adjustment:
Dip switches and a lookup table. | Micro proc controlled push
| button setup with LED display.
Frequency stability:
+/- 1khz maximum 500hz typ. | None given. (However, I found
| the drift within 1 Khz by
| raw measurement with a freq.
| counter.)
HI frequency suppression to prevent 19k pilot heterodyne:
Brick wall filter using multistage LC type | Brick wall using switched
circuit.... | capacitor chip. (DSP)
(Yes, the brick wall filter is necessary. It helps to eliminate weird squeals
and funky sounding heterodynes in the high frequency audio. Also it servers
to cut sampling garbage coming from (even expensive) CD players)
Audio specs:
For the entire system: 30hz to 15khz flat/rel-| None were found; glowing
ative to 50 or 75 us preemphasis... | accolades on "professional
45 db multiplex separation. | sound quality" abound...
| Brick wall is supposed to
60db sn for individual components, total unk- | cut off at 15 Khz.
own at this time. | Bass response of my stock
| unit was real poor (-20 db
| at 100 hz) see mods.
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How much does it cost:
Does not include postage assembly or tax... prices may vary...
1 watt _PLL_ transmitter kit $125.00 | FM100EX 1 watt kit $329.95
Stereo Coder unit kit $ 39.95 |
2@ mono limiters/brick wall |
filter unit. ($59.95 each) $119.90 |
total --------- |
$284.85
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*NOW*, to get the equivalent functionality we need to add the following
items to the _Veronica_:
(This is assuming a total newbie wants to get going and that they do not
have a well stocked electronics gadget supply.)
A case to house the _Veronica_ | Nice looking case comes with
would run in the $20 to $40 | FM100. It looks like a small
range for a fairly Spartan | signal generator.
looking enclosure..........$ 30.00
A 13.8 volt (3a) regulated | 120 vac power supply built in
power supply (like Brewers | which is converted and regu-
sells).....................$ 29.29 | to various DC voltages.
A microphone/2 line mixer/ VU meter | Builtin 1 ch mic and 2 ch
(using Ramsey's MX10 for | line level mixing, LED bar
an inexpensive example)....$ 69.95 kit | graph VU meters.
$ 29.95 case/knobs | Limiting function in mic ckt.
(The Radio Shack 320-1101A | The FM100 kite are 100%
mixer is in the $120 range | complete.
last time I recall checking
on one.....FWIW)
This now brings a lowside
estimate for materials to---------- | FM100EX: Still $329.95
$444.70 If I added right.
My guess is closer to $500 to do justice to the _Veronica_, by the time one
uses a big enough, clean looking chassis to mount all the components in
one place.
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What ya get:
_Veronica_ is English | Ramsey KIT is US origin |
This is really no big deal unless one is just a little too patriotic...
Then it's likely that they wouldn't be involved in microbroadcasting,
or would they?
Both kits as they come require about the same of assembly time. There
are about the same amount of components to stuff in either kit....
The folks at Brewers said that the _Veronica_ may be slightly less....
For a newbie, the Ramsey kit would be much easier to build since the
documentation is better in this respect. It took me longer to get the
Ramsey together... but not much.
Now add to the _Veronica_ the time to put it and a power supply and
perhaps a mixer/jack/VU meter unit into one case... the assembly
time could easily double. It did for me. The typical newbie
and a lot of old timers aren't real good at sheet metal working; who
knows how pretty the finished product would look? Of course one
could have the PC boards just laying around on top of a table......
not a very good way to protect and shield a quality product.
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Kit quality:
)component quality
)PC board: The Ramsey PC board is a much higher quality than the
_Veronica_, however, the _Veronica_ is quite adequate for
this type of project.
)electronics The electronic components are quite comparable and appear
to be good quality.
)other
) component technology: _Veronica_ tends to use more discrete ICs while Ramsey
went for the High tech route and used a micro controller
and single chip design for the _PLL_ amd LED drive.
Assembly manual: _Veronica_ manuals are OK and accurate but very terse.
Not very friendly for a total newbie, OK for experienced
kit/electronics builders.
The Ramsey manual is very user friendly and is 99.9%
accurate (I found a couple of mistakes in the manual)
and since the FM 100 is more complex, the manual was
much more descriptive of various electronic processes.
Schematic: Both companys schematics were lacking:
_Veronica_ doesn't put part values and sometimes
IC pin numbers on their schematic.
Ramsey should have used a B sized drawing for the
schematic since it is quite hard to read without
using a fairly stiff magnifying glass.
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Audio quality: (For me, this where the rubber meets the road!)
The _Veronica_ has excellent audio quality and without actually measuring it
I am sure that it exceeds or meets the published specs. Good strong bass
and the treble doesn't squeak with the 19khz pilot of the 38 Khz DSB signal.
The signal to noise ratio is excellent with the limiter/filter installed
and the stereo separation is also quite good.
* * * * * * * * * * *
The little Ramsey, on the other hand, did not work well with audio signals
for me when it was first turned on. All the functions worked and it tuned
up right but the audio basically sucked turds!
In order to fix this I ended up making several _modifications_ to the
_PLL_ circuit to clean up the audio and enhance performance. Even so,
the truth is: BA1404 ICs are NOT designed to be VCO controlled by a
single ended _PLL_ drive circuit.
The limitations of the _modifications_ make the Ramsey cleaner but not as clean
as the _Veronica_.... but then again if one is into Rock or some other type
of popular format rather than classical or new-age music then the difference
won't be noticeable. Also the mods make it necessary to retune the VFO
(L1 on the PC board) for frequency changes of more than a few channels, but
this is no different than retuning the _Veronica_; so this is a 'draw'.
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Mods:
The only mods I made to the _Veronica_ were to put a potentiometer in the
38khz DSB signal line to be able to max out the separation. Also
put longer wires on the LEDs so I could route them to the front panel
of my case rather than sitting on the PC board.
Ramsey FM100 mods: (From a kit builders report I published earlier this year)
1) C58 and C72 in the audio circuit are installed backward if in accord
with the written instructions and markings on the PCB!
2) My FM100 has poor or nonexsistant stereo separation and the 19 khz
signal tends to react weirdly to the tuning of L1. Also the the signal
to noise ratio of the dead carrier is unacceptable (say 40 db s/n typically).
The audio is better at the top end of th band but is really distorted at
the low end of the band.
The primary source for this problem is the _PLL_/Filter circuitry.
Since a .01 uf (10000 pf) capacitor is used to couple the FM
modulator/tuned circuit, it is easy to figure that some of the 38 khz
dsb signal (L-R, which generates stereo separation) will pass through C13
back into the _PLL_ filter. This will cause the L+R vs the L-R levels to be
unequal and separation to be lacking or strange. Also this path will
allow the high frequency edges of the _PLL_ to FM modulate the Varactor
and L1 tuned circuit. The _PLL_ signals will also interact with the
19khz pilot signal too.
One mod is to remove the .01 UF capacitor C13 (which couples the _PLL_
to the varactor and install a (20pf to) 300pf silver mica capacitor.
This cleared up problems big time but there were other little
things that bothered me..... the signal is still just a bit noisy.
I added a 470uf aluminum bypass capacitor to the junction of R8 and R7
(across C9) to help keep out the bass rumbles and sub sonic trash. This
will make the _PLL_ rather slow to lock up but is worth it if clean bass is
needed. I also added a 1kohm pull down resistor to the output pin of the
_PLL_ to make the lockup time more responsive. Also, adding a 100 UF tantalum
capacitor directly across the VCC and Ground pins of the _PLL_ will clean
up annoying heterodyne sweeps in the background.
To tune up... set desired frequency and adjust L1 so that about 2.5 volts
is present on the _PLL_ test point. This will minimize the interaction of
the varactor diode and the audio modulation and the _PLL_.
3) Preemphasis and the ability to specifically set the deviation level high
enough to over deviate seem lacking.
Placing a 10k ohm resistor in parallel with a .0022 uf capacitor connected
to (in parallel with or replacing) R34 (and the same for R72) will brighten
things up a lot and boost the audio levels to a usable point.
Two things will happen. One is that the deviation level controls (R23 and
R25) need to be turned down to about 1/3rd open. The result is that at 0
on the level meter, about 80% deviation should be easily obtainable for
the typical rock CD. This leaves a little head room for dynamics and such.
Another good thing that happened is that the apparent stereo presence
is improved by having more high frequency present. Since the signal is
being preemphasised after the 15KHZ cutoff filter, the signal doesn't
have a tendency to distort by heterodyning with the 19khz pilot signal.
However, it has been observed that if the level is turned up too high
that the high end may at times cause a bit of harshness.... this is
where a good limiter would be useful in the audio chain.
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I am satisfied with my FM100 and with a little tweeking I am
delighted with how well it works.... for the money spent. I use
it to rebroadcast the Dish TV radio signals around the house and out to the
yard and it works very well for this as well as being a backup transmitter
for the _Veronica_.
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ON the other hand, I won't give up my _Veronica_, even though I spent
a lot of time, in addition to building it, to case it up and build a
mixer for it. The _Veronica_ is unbeatable for audio quality and stability.
*************************************************************************
The _Veronica_ 1Wpll with accessories is more expensive to build all the
way up from 'scratch'. Assembly time is roughly twice as long if ya
do a good job on the case/chassis. Other electro-mechanical shop skills
are needed to make it look and function well. The sound quality can't
be beat for the money.
The Ramsey (with mods) works well and everything is in one case (supplied).
The new kit builder can actually learn something about electronics,
rather than Adept Board Stuffing 101. The completed kit really looks
sophisticated in it's own right and and the whole setup costs less.
Both kits have their pluses. Both kits fill a need and a niche.
Both kits have their minuses. I wish there were an assembled unit that had
everything... and only cost a buck 2.98.
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Don't buy an FM100EX or _Veronica_ 1w _PLL_ until you see
this:
COMING SOON! HYPER KILLER MOD THAT MAKES THE FM100
FUNCTION *JUST AS WELL AS* THE _VERONICA_
1WPLL with stereo coder!!!!!!!!!!!!!!!!!
for less than the cost of the FM100EX.