ABOUT THE BULLDOG WATTMETER
As many other manufacturers do, we advertise that the Bulldog is made in the USA. This is true. All Bulldogs are made in our facility in Old Hickory, TN, which is near Nashville. At present three people build the meters. My task is the final assembly and calibration. Others simply prepare the cases and hardware for assembly. Most of the hardware is obtained from American sources but some material does come from other countrys such as Japan and China.
Calibration of the Bulldog is made under perfect conditions. Our load measures 50.5 ohms. All measurements are referenced to an inductry standard. Accuracy in the field is assured to be accurate if the users load is at or near 50 ohms. Any measurement of reactive loads will degrade accuracy.
On the subject of AVG and PEAK, the Bulldog can be referred to as a passive peak reading meter. Active ( battery or DC powered) reading peak meters are available from other manufacturers if that is what you need.
The Bulldog does read a peak value of the sampled signal. The peak reading is passive in that when PEAK is selected a capacitor is placed across the incoming rectified RF signal. This allows the DC signal to be stored temporarily (while the user is transmitting) in the capacitor and not completely used by the meter coil. The value quickly reaches a peak and responds quickly to the input signal as long as the signal is there.
While a peak reading is important to a few discerning operators, to most users the Bulldog gives the operator a good indication of modulation ( swing ) on AM. You should feel confident that your Bulldog meter is indicating a peak value although perhaps not quite as accurate as a powered (active) meter. You'll never have to question the reading because the battery is getting weak. You'll never have to replace the $3 ~ $4 battery (the Bulldog has none) in your Bulldog wattmeter so your peak readings will remain constant with use.
METER SCALES, RESOLUTION and accuracy
RANGES
Scale resolution is somewhat different with the Bulldog wattmeter. Perhaps a detailed explanation can explain it for all. There are three scales: 0 to 25, 0 to 50 and 0 to 100. The first scale has positions at 0 - 2.5 - 5 - 10 - 15 - 20 - 25. These divisions are indicated with a large round dot or ball. The second scale has positions at 0 - 5 - 10 - 20 - 30 - 40 - 50. The third scale has positions at 0 - 10 - 20 - 40 - 60 - 80 - 100. All of the values align to the same indicator or dot.
RESOLUTION
The Bulldog wattmeter has only one marking between these divisions where other meters may have up to ten incremental markings between the values on the scale. New CB users might find this odd when comparing meters. Still experienced users can usually make the division themselves. We could have made the meter scale the same as other manufacturers but the Bulldog was intended to be different in more than just this scale resolution. Surely everyone knows that 70 would be the half way reading between 60 and 80.
No user has ever mentioned having any problem reading the scales. If you need to know if your reading is 825 watts instead of slightly more than 800, then perhaps you are a discerning operator and need better resolution which is available in meters costing much more.
ACCURACY
Bulldog wattmeters are naturally at least 7.5 times more accurate than a majority of other analog wattmeters you can buy. Practically all other wattmeters use a factor of 10 between meter ranges. This is equal to a meter with two or three ranges like 20 - 200 - 2000. Some meters are slightly more or less but a normal range multiplier is 10. Each range then measures ten times the previous.
The Bulldog, with 10 ranges, has no more than a 2.5 multiplier. It is therefore normal to expect a Bulldog to be 7.5 times more accurate than the others when using the 25 - 250 - 2500 ranges. The other ranges have a multiplier of 2 so the these ranges are 8 times more accurate. This brings us to one of the main factors in the overwheming acceptance of the Bulldog to CB enthusiasts.
In operation you can be assured that 25 watts of RF on the 25 watt scale will also read 25 watts on the 50, 100 and 250 watt scale. The same can be expected when using the HI range. No other analog wattmeter even comes close. This type of resolution was obtained by extensive reseach in the design of the RF sampling sensor. Many sampling circuits were employed in the prototype designs. All other circuits utilized, degraded the accuracy when reading the same output over several ranges. We believe this degree of accuracy should be the standard expected of all wattmeters. Compare the features against any other analog wattmeter and the Bulldog stands alone...
READING SWR
Reading SWR or the reflected power is another method that is different than any other wattmeter and may take a little getting used to for the casual CB user. Users have picked up on the method with ease.
There is no SET or Sensitivity control on the Bulldog meter. Using the many ranges available with the Bulldog the operator can simulate a control by setting the range switches to produce a full scale reading. By selecting other switches in addition to the scale at hand the wattmeter will give the user the ability to get very close to full scale. Then simply set the switch to REF and measure the SWR directly on the scale. Here is an example of how this can be done:
We measure the radio output and see that it is about 5 watts on the 10 watt range switch. We need a full scale reading to read SWR directly but modulating the signal at this power level produces too much signal. All the user has to do is select the 10 watt and the 25 watt switches together. Now the meter will read ~5 watts full scale. Flip the switch to REF and read the SWR directly. Do not be concerned that the FWD signal may be slightly over or under a full scale reading. It will not affect the SWR reading by any significant amount. That's how it is done. Use the same method for other less than full scale signals or you can even modulate the signal to get it full scale. Remember that when you require an accurate wattage measurement only one switch can be selected.
REMOTE SENSOR OPERATION
The remote sensor is in a small cast aluminum box about 1/2 the size of the Bulldog wattmeter. This box contains a through line sensor and electronics exactly like the Bulldog meter input circuitry. The remote has a 20 ft cable that attaches to the Bulldog meter with a 1/4 stereo phone plug. Input and ouput connectors are labeled. Both forward and reflected levels can be read on your Bulldog meter when using the remote sensor.
CONVERTING NON-REMOTE METERS
Those with normal Bulldog meters can have their unit converted to remote operation by returning the meter to EFJ Devices. The charge is $50 prepaid by money order. Personal checks are OK but must clear first. This delays the shipment by 7 - 10 days.
We can return the converted meter UPS GROUND COD CASH for a total fee of $60. You pay cash at your door. You get your converted, updated Bulldog meter and a matching remote sensor. Call if you have any questions about obtaining or using the Bulldog meter with a remote sensor.
It is our hope that you never encounter difficulty using your Bulldog wattmeter, but if you do need assistance or suspect the meter is not performing as indicated then feel free to contact the dealer, the distributor or contact EFJ Devices for further assistance. You may even return the meter to us to for a complete checkout and/or repair without consulting the seller. Your meter will be returned as soon as possible without charge to you.
</p>