|
New to Ham Radio?
My Profile
Community
Articles
Forums
News
Reviews
Friends Remembered
Speak Out
Strays
Survey Question
Operating
Contesting
DX Cluster Spots
Propagation
Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers
Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net
|
| Reviews Summary for Collins KWM-2/2A |
|
You can
write your own review of the Collins KWM-2/2A.
|
WA0IIH
|
Rating: 5/5
|
May 9, 2008 15:09
|
Send this review to a friend
|
|
The best Collins rig!!!
|
Time owned: more than 12 months
|
|
Got my first KWM-2/A in 1973 after getting my general license. I worked all summer to pay mom and dad back for the funds they loaned me. To this day I still consider it to be the finest transceiver ever built and own five of them, two KWM-2 and three 2A models. I do repair and restoration work on vintage tube gear for myself and fellow hams and have serviced just about all makes and models in 35+ years in the hobby. Art Collins radios are in a class by themselves, the quality is not to be found in any other rig. I operate my radios on a daily basis, the only "new" radio at my qth is a Drake R-7A general coverage receiver I bought new back in 1981. I dont need computer control, or a speech processor, auto memories or automatic tuning. I have been peaking the grid, dipping the plate all my life in ham radio and have no complaints!! My KWM-2/A rigs along with a D-104 give great audio reports and a couple of 30L-1 amps give plenty of RF into the antenna. Find a nice one and have the time of your life!!! These radios with their warm glow will be all that I will ever use in the hobby. By the way, I saw my first one back in the early 60s as a youngster when the ham radio bug bit me!!! Real radios glow in the dark!!!! 73s WA0IIH
|
|
WA0ZZG
|
Rating: 5/5
|
Feb 3, 2008 09:05
|
Send this review to a friend
|
|
Historical
|
Time owned: months
|
It's interesting to see this radio still alive. My first job, out of school in 1969, was Collins Radio in Cedar Rapids. I then had a Tech. Collins encouraged me to get at least a General and an Elmer found me a KWM-2/516F-2. It didn't completely work and needed aligned. I think he planned it that way. I was also given two copies of the service manual(new and old) and a little book on the basics of SSB. Parts were always available as was answers to my questions, but it was my job to finish it. Once it was on the air, a equipment pass was given to me and a time set for me to take it to the final assembly line to have it evaluated. I'm still not sure if the radio was graded or me. A couple of tubes were changed and the I.F. was touched up and it (or me) were given a clean bill. I also worked the assembly line on 20M, but no QSL was allowed. I used it for 18 years, along with a 30L-1 before upgrading. The 30L is another story. My Elmer is still around(K0QKR) he had KWM-2 s/n 5. There is no finer way to learn the art of SSB HF comunications. To those that still use these, keep those trimmer caps clean. They will go intermittant otherwise. Use it on the air.
Dave
WA0ZZG
|
|
KC2NYQ
|
Rating: 5/5
|
Feb 3, 2008 07:57
|
Send this review to a friend
|
|
One great transceiver
|
Time owned: 6 to 12 months
|
|
This is one fine radio. It looks and performs well. I've worked several DX stations and have always received great audio reports. If you can afford it then go by one. This is one of Collins best.
|
|
N2DTS
|
Rating: 3/5
|
Nov 17, 2007 19:49
|
Send this review to a friend
|
|
great looking rig
|
Time owned: more than 12 months
|
Yes, it looks great, its quite robust, but its an old radio, and you have to tune it which can be a pain by todays standards.
Its fine if you hang around one frequency, but jumping around requires lots of tuning.
Receiver performance was ok in its day, not so good by todays standards, and it was always poor on CW because of the audio generated CW.
Like any piece of Collins gear, stable and accurite in frequency, built using quality components, and great looking.
If you can get one cheap, go for it,they are fun, and you can fix them, but I dont think they are worth some of the prices I see them go for these days.
|
|
KC0NJD
|
Rating: 4/5
|
Aug 11, 2007 01:41
|
Send this review to a friend
|
|
good
|
Time owned: 3 to 6 months
|
|
well i own one been whanting one for a long time about 4 years and finally got it of course had to do horse trading to get it but any how i had it gone thrue by a ex collins of 14yrs of servic he did a great job on it i plan on keeping this one it is my main station rig which i do own a few newer rigs but this one is a eye catcher every time i come in to my shack to get on nets i have worked dx with it so there you go no complains here yet like they say tubes do glow in the dark wow i love it 73 every body
|
|
W9CTY
|
Rating: 5/5
|
Apr 8, 2006 18:18
|
Send this review to a friend
|
|
Forty one years and counting
|
Time owned: more than 12 months
|
|
This is one of the classic transceivers from the 60's that was built with military quality and capable of operating under the most extreme conditions. I took mine all over the world in its custom Samsonite suitcase and it never failed to operate after some very rough flights. It still works and there's never been a solid state rig with the audio quality of tubes.
|
|
WIRELESS
|
Rating: 4/5
|
Feb 8, 2006 12:31
|
Send this review to a friend
|
|
Still a desireable radio
|
Time owned: more than 12 months
|
The Kwm2 is a good radio in its "day" and now. The receive and xmit audio is good, the filtering is excellent, stability is very good, and takes minimal funds to keep working. The only parts I ever put into an 'm2 was tubes which are still available and will be for a long time. This is significant. What are owners of the new radios going to do when those tiny screens or OEM parts inside crap out and are not available. From what I am hearing owners of the Icom 756 can't buy replacement screens anymore. (screens in the original 756 seem to have problems) If this is true (it will be if it isn't now), these $3k radios are going to be dead boatanchors sooner than anyone thought. And the other new radios will end up with the same problem.
I still like my m2 and will probably keep it forever. I think it will work indefinitely even when some of my newer radios die.
|
|
W8ZNX
|
Rating: 4/5
|
Feb 8, 2006 11:30
|
Send this review to a friend
|
|
thing of beauty, dog on cw
|
Time owned: more than 12 months
|
first used KWM-2A in the Army Signal Corps
every signal company had a few KWM-2A's
kicking around
mostly used when seting up microwave shot
they were some of the most abused radios
iv ever seen in my life
thrown in the back of duce and a half
and left their, rained on
dryed in the sun days later
during monsoon season
just moved to a warm spot
near or on top of running microwave gear
seen used to hold down tent flap
when a sand bag was not handy
bashed, battered, chewed up,
knobs missing, meter glass cracked
nearly packed with mud
( not talking older open frame relay kwm-2 )
some how they still ran when needed
only had to change tubes now and then
Collins S line radios are a thing of beauty
sold my kwm 2 last year
got to be worth too much money
have too many other xceivers worth lots less that run rings around a kwm-2
still keep my 75S-3B
will stay in shack till the sk estate sale
radio is as close to unuseable on cw
as you can get
and still have place to plug in a telegraph key
truly a dog on cw
expensive as it was and is
you think Collins Radio could have made
it work better on cw
to me any hf rig that does not work well on cw
can not be given a rating of 5
was tempted to give the radio a 3
mac w8znx
|
|
AC5XP
|
Rating: 5/5
|
Aug 18, 2005 10:35
|
Send this review to a friend
|
|
This is the '56 Thunderbird of radios
|
Time owned: more than 12 months
|
The Collins KWM-2A
By Loek d’Hont, AC5XP
The Collins KWM-2(a) is a HF SSB transceiver capable of transmitting from 3.4 MHz to 30 MHz with some band exclusions. Both USB and LSB are supported as well as CW, the latter using the SSB filter so no narrow-band CW operation is possible. The design stems from the mid-fifties and as such it is a "hollow-state" radio, you won’t find a single transistor in this radio.
This transceiver is to a radio collector what a ’56 Thunderbird is to a classic car collector. Better cars were built in ’56; but the Thunderbird is the one. And the challenge is to get one as close to mint as possible. It is the same with the KWM2(a), and as such the downside is that acquiring one is going to set you back considerably from a financial standpoint, especially if the radio is in excellent condition.
A lot has been written already about this radio’s history, so I will limit myself to the essentials. The radio was the successor to the KWM-1, a conceptually almost identical Collins radio that covered only 14 MHz to 30 MHz. At the same time the KWM2(a) was designed more with cost in mind than the KWM1 was; I’m trying to avoid the word "cost reduction" here. The KWM2A was also used by the US military, although not in tactical situations, only in supporting roles. For that purpose, Collins equipped the KWM2A with PTFE insulated wiring, something the KWM2 does NOT have, only for very late models.
Today, the KWM2(a) is a Collins celebrity which fact can cloud one’s judgment. So let us now look past the radio’s celebrity status and consider the technical aspects.
The radio is designed as a general-coverage dual-conversion concept, with the first IF variable, from 3.155 MHz to 2.955 MHz. The second IF is fixed at 455 kHz, designed around one of Arthur Collins' famous mechanical filters. It differs from competitors mostly because the KWM2(a) was truly general coverage in concept, a rarity for a ham radio in those days. But easy to accomplish for Collins because it has successfully pioneered general coverage concepts as once can see in the professional Collins radios from the same era.
The concept for the KWM’s variable second IF allows for the low-frequency VFO to be directly injected as the transceiver's second local oscillator (LO); the first LO is fixed (within the selected band) and comes from a banked crystal oscillator. Other radios of the time often have the second LO fixed and create the first (variable) LO by mixing a low-frequency VFO against fixed crystals which then creates a variable first LO. In this Collins concept one avoids the VFO mixer, which eliminates the associated spurious problem that can be caused by such mixing. Minor downside is that no in-band selectivity is to be expected from the first IF in this concept, so the second receiver mixer needs to be at least as good as the first one if one is to avoid overloading from close-in signals.
The low-frequency VFO range is only 200 kHz (from 2.5 MHz to 2.7 MHz) where other radios of the era often used a 500 kHz span. Upside for the 200 kHz span is that the narrower range improves over-all stability for the VFO, downside is that MANY crystals are needed to cover a large frequency range for the radio, in theory one would need 132 crystals to cover the full band of 3.4 to 29.8 MHz in 200 kHz steps. A crystal pack exists for the KWM2(a) to do exactly that (minus some band exclusions), as the switch wafer and internal crystal banks only allow for 14 crystals per bank, thus 14 bands. And by the way, this is also where the main difference lays between the KWM2 and KWM2A; the "A" version has TWO crystal banks of 14 crystals each; the KWM2 only has one. For the rest, the radio concepts are identical for the two radios.
The radio uses only one filter in the second IF, obviously because these mechanical filters are not cheap. Therefore, two sideband crystals are needed if one is to generate both USB and LSB. To compensate for the 3 kHz in frequency shift that this causes, Collins added an adjustable capacitor to the VFO to cause a 3 kHz compensating shift. If this compensating capacitor (and the associated inductor to keep the dial linear) is perfectly aligned, you will not hear a difference when being tuned zero-beat to an AM broadcast station and then switching from USB to LSB. The reality is different, even if one is to set this up perfectly it will drift away after a while. I therefore would have preferred the use of two mechanical filters instead for this radio, one for USB and one for LSB and using a single sideband crystal instead. Basically the same way the Drake TR-4 does this, and all of Collins professional radios that are capable of both USB and LSB.
How does the radio behave on-the-air? The transmitted SSB is excellent in quality and can compete with anything on the market today, no question about it. The two 6146 tubes in combination with the excellent mechanical filter will assure this for years to come.
The receiver is very sensitive and a joy to listen to, again, because of the excellent mechanical filters. The absence of any group delay in the filter makes short-wave listening an enjoyable experience with this radio.
The dial mechanism that drives the PTO (Permeability Tuned Oscillator) works perfectly without any backlash and "feels" very good. The way Collins designed the changing 10-kHz indicators on the dial is outright ingenious; one sees it go from 0 to 200 kHz on the SAME dial disk, after TWO full resolutions. A very nice tough.
Also, the linearity is excellent and allows (in combination with the crystal calibrator) to be within 200 Hz of a pre-chosen spot frequency. Also, VFO drift is very low, quite an accomplishment if one considers that this radio uses a tube for the VFO. Last but not least, the AGC function of this radio works very well.
One should not expect miracles from the radio’s large-signal handling capabilities; this is where modern radios have gotten better. It is on par with its contemporaries of the time (like the TR-4) but a Collins R390 receiver is much better for this aspect.
The PA and RF sections need to be tuned from the front controls after each frequency change, but it is easily achieved. The large S-meter is a pleasure to look at. It is also used to monitor PA bias settings.
Unlike some of my fellow collectors, I do not want to raise this radio to sainthood, so one needs to be open to the downsides. What is it I do NOT like about the KWM2(a)?
-->THE absolute winner in this category: The RCA-style CINCH connector Collins picked as the antenna connector. How the heck did Collins come to this decision? We will never know. It is not even a good one; it is very low in profile so there is little grip for the shroud from the mating connector that one would use. One is tossed between two choices: Leave as it is and live with the poor connection, or replace it with a better RF connector. Of course the latter violates authenticity (AND will lower the value of the radio), so no collector in his right mind (including myself) would replace this connector.
--> The fact that only a single filter is used instead of two (one for USB and one for LSB). Not a killer but two filters would have been nice.
--> The way the sideband crystals are soldered on the mode switch. Very poor; it looks like a CB radio concept. Collins should have placed the two crystals on a socket at the chassis, like it was done for the 100 kHz calibrator crystal which resides on the chassis, socketed.
--> The fact that AM is missing; funny that Collins went "Cold Turkey" on that one for this radio. Collins has a rich history in AM; it therefore should not have been neglected on the KWM-2(a)
--> The flimsy mount for the "not used so often" adjustments on the inside. Especially the one mounted on the meter connections; because of that concept it also is a bear to replace the meter bulb. This must have been an afterthought during the development.
--> The poor conducted-noise rejection on the second IF. If you hear a nasty humming signal at S9+ that repeats itself at the same dial spot when band changing, you are receiving the signal from your RCA "phone extender" that transmits across the power lines in your house. That is, if you have such a device (which I do for the phone hookup that my satellite receiver requires). The carrier frequency used by this device is exactly within the variable second IF range that the KWM2A uses. It is possible that the use of a good EMC filter before the radio's PSU power cord will fix this, I haven't tried this yet.
--> The fact that the PA tube filaments cannot be turned off if one wants to do listening only.
As you see, all are relatively minor; the radio is a pleasure to use, but also to look at. I know; the following statement has been over-used but I will say it anyway because it is so very true: "A real work of Art – No pun intended" (duh)
Some tips for people that are considering the purchase of this radio.
--> Get the version with the PTFE wiring (all KWM2As and late KWM2) because the older PVC insulation gets brittle and is more difficult to work on when you have to conduct repairs
--> Apart from the PTFE wire issue, do not focus too much on the KWM2A. A late KWM2 might be a lot cheaper and is just as much fun to own and use. That extra crystal bank in the KWM2A you won’t really use anyway.
--> Make sure that your radio has the replaceable relays (all KWM2A models and later model KWM2)
--> Do not focus too much on a VERY late model KWM2A. Apart from the fact that you will have to give up your first-born, there are two downsides on such a radio: The plastic trim-ring, AND it uses a lower-cost plug-in mechanical filter in a plastic case (FA style) that I have found to be much more susceptible to aging than the all-steel-and glass-insulation that is used for the older radios (this is the "Y" filter style) . This is not just my "opinion": I have owned a very late KW2A that needed to have the plastic FA filter replaced. $300 from Nebraska Surplus! By the way, the Y style filter is also used in a lot of Collins professional radios of the time (618T for instance that I also own). They are Collins best filters ever made (for the best RADIO Collins ever made but maybe I will write a review on the 618T another time)
--> Restoring this radio is not easy. I would therefore buy it as good as you can find it, within your budget constraints of course. For instance, forget about applying a new screen-printed lettering for the front, a major undertaking. Same for fixing a corroded chassis: Almost impossible and it will never look as new any more. Just spend the extra dollars and get a good one from the start.
--> Do not focus on available accessories too much, like the Waters rejection tuning and the noise blanker. They are "nice to have's" but the performance of these extras cannot compete any more with modern radios. Only go after it if you MUST have it from a historical perspective.
--> You will NOT be able to see the imperfections on those Ebay pictures. Demand from the seller to send you high-resolution pictures from all sides (INCLUDING the back), before you place a bid. If he does not do that, do not bid. I should know; my first KWM-2A was like that. A pleasant side-note here: I still sold it with a profit, WITH disclosing the problems to the buyer. That shows you the prices these radios fetch nowadays…
--> The dark-grey paint on the "leather-texture" front is of superb quality and will resist goof-off solvent. The white lettering, on the other hand is of VERY POOR quality. Do not use ANY chemicals and/or excessive rubbing on this because it WILL come off. And like I said, restoring the white lettering is almost impossible.
Now for the big question: What would I have to rate this radio? In terms of performance and versatility it is a 5, but it is so heavily overpriced that a 4 would probably be more deserved. Why do I say this? Simple – My mint Drake TR-4 was a LOT cheaper and is just as good if not better.
However, this is where the KWM-2(A)’s celebrity status starts to intimidate me – I would not DARE to give it a 4, hi.
Nobody is perfect....
|
|
WN9PIQ
|
Rating: 5/5
|
Nov 18, 2003 15:43
|
Send this review to a friend
|
|
A True Classic
|
Time owned: more than 12 months
|
|
For years I dreamed of having a Collins radio...perhaps only for snob appeal. Then as technology moved on, the tube-type radio seemed irrelevant. Having owned both a winged and now a round KWM2, I can tell you that its no wonder these radios are still regarded as one of the best ever produced. The receiver is simply outstanding, audio quality is great and signal reports from other stations are ALWAYS good. Oh, and they still have great snob appeal, for those who have this as their motive. :") If you've always wanted one, get one !!!!!
|
|
If you have any questions, problems, or suggestions about Reviews,
please email your Reviews Manager.
|
|
|
|
|
