The 6146 and the 6146A / 8298 are enough differnet from the 6146B / 8298A that problems happen in a number of transmitters.  Collins had to make changes in production on the 32S3 and KWM-2 series so that the 6146B / 8298A would work.  The older units, unless modified, should no use the 6146B / 8298A tubes.

The same thing goes for other equipment.  Some will work fine, while others will not.  The operating parameters of the 6146B / 8298A are somewhat different from the 6146 / 6146A / 8298 series.  This can produce spurious emissions which can cause the tube to overheat as well as causing problems to other radio services (TVI, etc.).

The 12 volt equivalents which are the 6883 / 6883A / 8032 tubes are different from the 6883B / 8032A / 8552.  Motorola, a number of years ago, decided just to furnish the later series of tubes even though many of their Motrac radios used the earlier.  The 6883B / 8032A / 8552 tubes when used in the radios designed for the 6883 / 6883A / 8032 tubes immediately overheated due to spurious emissions, and within 0.5 hours of use the glass envelopes of the tubes shattered due to excessive heat.  This "cost saving" effort by Motorola (by not having to stock two different types of tubes) eventually cost them "mucho" money because they had to not only replace the tubes with the correct version, but also had to "foot" the bill on the repairs.

I have the following transmitters which DO NOT like the 6146B tubes:  Collins 32S1, 32S3, Heath DX-35, DX-100, Apache, Seneca, SB-110A, SB-401.  In addition, I have owned both Knight T-150 and T-150A, neither of which liked the 6146B.  I owned a TS-520 for a short while that had 6146B tubes installed and they were bad.  Went to the 6146A and it worked fine.

The 6146W tubes, depending on year of manufacture, can be either the 6146 or 6146B equivalent.  You cannot tell from the model number.

By the way, the 6293 is a variant of the 6146 / 6146A that will work fine in the older rigs and is a "ruggedized" version.

Glen, K9STH

All license information is in the public domain by federal law.  The FCC must make this information available.  There are also things like QRZ.com, the Callbook, etc., that publish your address, class of license, etc.  This information is used by other amateurs to send you QSL cards and the like.  The information is also available to anyone including those who are engaged in selling items to the amateur radio operator.

The same thing holds true for your driver's license, automobile license, etc.  Your state is required by law to provide this information under the open records laws.  The same thing is true on real property, business licenses, sales tax permits, etc.

Present International regulations call for a code test for operation below 30 MHz.  The FCC has done all that it can (legally) by dropping the code requirements to 5 w.p.m.

The "toll tags" on your car for things like the bridge are "passive" devices.  That is, they don't have a built-in transmitter.  They are activated by a short-range transmitter that is contained at the toll station.  The "toll tag" acts as a transponder which "bounces" the signal back to the toll station with the billing information attached.  I have one on each of my cars for the toll roads in the Dallas, Texas, area.

Your microwave oven is probably operating at a frequency around 2.4 GHz which is outside of the range of your counter.  Also, it is supposed to be shielded which would keep the r.f. level below that which would "trigger" the counter.  If you could read the frequency, you would probably be getting a pretty high "dose" of r.f.

Counters can be a bit "tricky" to use.  If the signal level is too little, or too great, they can give false readings as well as no readings.  I have a couple of counters and they can be very useful devices.  However, you must know how to use them and their limitations.  They are very useful if you don't know the frequency that the piece of equipment is putting out.  Also, since they are much less expensive than service monitors, they are a good item to use to determine just what frequency the device is putting out.

Service monitors are most useful when the desired frequency is known and needs only to be adjusted to "exact".  Frankly, there are many more counters out there than service monitors.  You can get a pretty good counter for under $100 these days.

One thing to remember is that no frequency determining device is "absolute".  They have to be periodically adjusted to a frequency standard (like WWV).  Too many amateurs with "digital" readout transceivers (etc.) seem to think that "they" are on the "correct" frequency when they can be several KHz off (in the worst case) because the frequency standard inside their equipment has drifted and needs to be recalibrated.

There are all sorts of educational, point-to-point, etc. video in the region around 2 GHz.

Basically, a "dial up" piece of test equipment uses switches (like on 2 meter FM rigs) to set the frequency.  Usually, there are switches to the nearest 100 Hz.  For example, to dial up 146.9400 MHz you would set the first switch to "1", the second to "4", the third to "6", the fourth to "9", the fifth to "4", and the sixth and seventh switches to "0".  The signal generated by the service monitor then would be within 100 Hz of 146.9400 MHz to align the receiver.  Also included is a calibrated attenuator going (usually) down below 0.05 microvolts.

The transmitter frequency difference from the "reference" frequency of 146.9400 MHz is normally displayed on some type of meter.  You adjust the transmit frequency standard to the proper frequency.  Modulation / deviation is normally read on either a meter or a built-in oscilloscope.

There are all sorts of other "nicesities" depending on the particular model of service monitor.

You can purchase signal generators, audio generators, and other pieces of individual test equipment with "dial up" capabilities.  Because of the much tighter frequency tolerances of this equipment it normally costs a bit more than the old "analog" type of equipment.

The receiver that I have seen on the Kon-Tiki clips on TV (i.e. Discovery Channel) is a Hammarlund NC-183D.  Don't know about the transmitter.

A service monitor is a combination piece of test equipment that normally includes a signal generator (digital model), a frequency measuring device (usually, but not necessarily, digital, can be a counter), modulation meter (or oscilloscope, or both), often a built-in wattmeter / dummy load, and usually a tone generator.

Usually the frequency coverage is up to either 512 MHz, or, more common, 1 GHz.  The most popular manufacturers of these include IFR, Cushman, Motorola, and Singer-Gertsch.  Prices new for these manufacturers start at around $10,000 and go up from there.  There have been a few lower priced units, especially those using a frequency counter instead of digital "dial up" that have started at around $3000.  In the two-way radio business these days, it is MUCH easier to use a service monitor than try to use all of the individual test equipment items that they replace.

There are service monitors available for other frequency ranges, but, they are a much more specialized piece of test equipment.

Actually, his question was on the subject of cellular monitoring.  For other services, it can be handy to use some type of monitor receiver including scanners.  When I was in the service business, I used to have quite a number of my customers' repeater frequencies in my mobile (including the proper CTCSS tone).  That way I could communicate directly with them if necessary.  Also, it was easy to check the repeater.

Service monitors have gotten a "bit" smaller these days.  However, all three that I have around the shack don't exactly qualify as being "smaller".  Of course, when I was in college, the frequency meter weighed about 50 pounds, the signal generator weighed about 35 pounds, the modulation meter weighed about 15 pounds, and the wattmeter (including spare "slugs") weighed about 5 pounds!  That, plus a tube caddy, tool box, etc. was "real" fun to take up a tower to do repair work on a customer's repeater /  base station!

As far as I can surmise, this would be someone engaged in the ACTUAL repair of cellular equipment, engineering personnel doing performance measurements on the cell sites, and the like.  However, the VAST majority (and I mean VAST majority, if not all) of those persons would have the proper test equipment to perform the tasks and not have to resort to things like scanners.

The holding of a General Radio Telephone Operator's licens granted by the FCC (replaced old "first phone" and "second phone") would be prima-facie evidence of a person authorized to do repair on cellular telephones (although you no longer have to have such license to work on this equipment except under certain circumstances).

I have held a commercial operator's license since September, 1962, have been (over the years) engaged in the repair business (worked my way through Georgia Tech as a two-way radio tech for Motorola), etc.  However, I don't have a scanner "modified" for the cellular frequencies.  Frankly, if I really wanted to listen in, I have service monitors, etc., that work very well.  However, I dislike scanners (they never "shut up") and am not interested in listening in on personnal conversations.

Frankly, the statement is just a "ploy" to put the burden of owning a scanner modified for cellular on the purchaser and not on the person doing the modification.  The person who modified the receiver can always point out that fact was "advertised" and that he/she did nothing wrong my modifying the scanner.  The person who "bought" the scanner was being "deceptive", not the person who modified it.

A series tuned circuit (coil and variable capacitor in series) will accomplish this as well.

I have used them for both receiving problems and for eliminating harmonics from linear amplifiers.  They work wonders for things like the 5th harmonic of 20 meters causing TVI or the 2nd harmonic of 10 meters, etc.  The "bandwidth" or "notch" can be varied.  You increase the inductance and decrease the capacity for a sharper notch.  To broaden the notch, you decrease the inductance and increase the capacity.  

These have little effect on the impedance of the transmission line (very high impedance except at resonance), especially if installed at the antenna connection of the linear, transmitter, etc.