Separate Transmitters & Receivers?
R. J. Cleve (KW4CQ)
on
March 15, 2004
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How long has it been since any of today's major ham transceiver manufacturers have produced a separate HF transmitter and matching receiver? I wonder why they no longer do? Is it a matter of economics, technological advancements, and easier customer support? Or, is it simply the result of a lack of interest in matching separates on our part?
I have always suspected that (even modern) HF transceivers were a compromise in terms of performance, functionality, and flexibility and that separate transmitters and receivers were superior in all respects.
I would like to hear convincing pro and con comments from both the manufacturing and ham community on this one.
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Separate Transmitters & Receivers?
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by KG4VPV on March 15, 2004
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For me its a matter of convenience. I know a lot of people out there love to operate equipment that is a big honking door stop, but I prefer it to be something I can take with me on the go. For instance, I like to do a lot of qrp backpacking, and there is something about a separate box for each is kind of a no seller for me, more space in the pack when its at a premium. I think also with the advent of the integrated circuit, things can be made smaller, and hence, they fit into a reasonable amount of space. While I am not totally close minded to the idea of a separate transmitter and receiver, it isn't for me. On the other hand, I believe there is a market for such a thing.
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RE: Separate Transmitters & Receivers?
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by LNXAUTHOR on March 15, 2004
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- separate transmitters and receivers continue to be produced and used to get on the air by many hams who subscribe to the principles and merits of operating as a "New American Amateur":
QRP ops!
- i my use my vr-500 as a separate receiver on occasion while setting up portable; quite handy for checking WWV (obviating the need for lugging around a clock or dual-time capable watch), various beacons, or band conditions before deciding on a starting frequency...
- kudos to the author for bringing up the subject!
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Separate Transmitters & Receivers?
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by N8YV on March 15, 2004
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Once upon an era, the amateur transceiver was viewed (correctly) as a compromise to a "proper" T/R arrangement. Convenience was gained, albeit at the expense of operating flexibility and performance. The concept of shared I-F strips and dual-purpose stages gradually became the new standard, concealed in part by advancements in solid-state technology.
As with many other technologies that "progress", something is usually left behind. Over time, the original reasons for separate T/R arrangements were lost. Because of convenience, cost concerns and lack of awareness, it is doubtful that a resurgence of T/R pairings will occur in modern gear. Separate T/R units were advantageous because each could benefit from its own design, without compromising in areas such as I-F frequency choice, conversion frequencies, and audio stages.
The problem today is not so much one involving receivers, as there are many fine examples of top-notch equipment out there even now---the Ten Tec RX-340 and Watkins-Johnson (now Signia-IDT) 8711A, are superb---and far outperform most transceivers. Several others, including JRC (NRD-545), Ten Tec (RX-350), ICOM (IC-R75), and Palstar (R-30) offer competitive performance and fairly reasonable pricing, considering they are stand-alone units that equal or rival many mid-priced transceivers.
Transmitters, however, are almost non-existent in the ham market, at least in terms of newer product. New Kenwood "twins", Drake C-line, and Collins pairs were common up until about 20-25 years ago, but even these are now relegated to collectible status and only available on the used-equipment market. It hasn't helped that much transmit-only equipment is clunky, older, and unacceptably large---in addition to being "drifty" and in need of frequent maintenance.
However, I have assembled a modern, well-performing station using new components, as recently as 2 years ago, and which can still be done as this is written. Using an ICOM IC-R75 and its near-twin IC-718, it is possible to bring back the ol' glamor of "separates" again. Relegating the IC-718 to transmit duties alone, the two units can easily be linked together by using 2 patch cables; one for C-IV control, the other for muting the R75 during Xmit.
The two units will "track" together (tuning one also tunes the other, etc.) in both function and frequency, at least from 160-10 meters. The two rigs look almost as if they were meant to pair-up, with nearly identical layouts and cabinet dimensions. The IC-R75 receiver is superior to that in the IC-718, with more noise-fighting and filtering options than are available with the 718, alone.
The only accessory that needs to be added, is a coaxial relay to protect the R75 from direct RF from the output of the 718, when using a shared antenna. Otherwise, separate antennas can be used, for example a vertical for the 718 and a longwire/dipole for the R75.
I put this station together for the purpose of combatting frequent S-8 interference noise, when I lived in a city home surrounded on three sides by utility power lines. The R75 was the only rig I found that could tame the effects of such interference, well enough to facilitate amateur communication. For under $1500, I had a T/R "pair" that met or exceeded just about any comparably-priced new transceiver available.
This can still be done today, with the price of both the R75 and 718 being at or near all-time lows. Add a good mic, power supply, and a couple filter options for the R75, and it still falls well-under $1500. The best part, is that if you already own a 718, you can add the R75 and the necessary extras for a very reasonable cost. There is something magical in viewing these two rigs side-by-side on the station desktop, especially in a dimly-lit or darkened room---they look awesome, in my opinion!
N8YV
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by KB7YOU on March 15, 2004
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Hi,
I'm glad to see this thread because I have been considering using my Icom 756 and Icom 706 in tandem with one acting as receiver and the other as transmitter. As the previous poster stated it's very easy to connect the rigs together via a simple cable and have them both track the same frequency and mode when the controls on one radio are used.
One question I have is regarding the safety of the receiver when the transmitter is transmitting. I'm using separate antennas separated by about 15' and even at low power, the receiver s-meter is off scale when transmitting. Is it safe to leave the receiver attached to it's antenna while the transmitter is on or should I use a tr relay/switch?
For now, I've decided not to take a chance and I keep the 2 radios on separate bands when they are both operating (usually I'm doing PSK-31 on 20m with the 706 while doing cw/ssb on the 756).
THANKS
Chris
KB7YOU
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RE: Separate Transmitters & Receivers?
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by AE4X on March 15, 2004
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Uh......No. Why?
We're running out of topics aren't we?
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RE: Separate Transmitters & Receivers?
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by W8MW on March 15, 2004
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KW4CQ: Thanks Bob for starting this discussion. I have reflected on this topic quite a bit over the years. When I was first licensed separate tx and rx hardware were the standard. As HF transceivers started showing up most of us felt they were a compromise and if they had any practical value it would be in mobile and portable applications. It sure didn't take long for manufacturers to move entirely toward single box technology. No doubt xcvrs simplified station construction and on air operation, but there were losses associated with that convenience. The most significant of those was our ability to keep the receiver live while transmitting. This gave us a method of monitoring our own transmitted signal. Not a synthetic cw sidetone or audio from a low level transmitter stage as is common with so called monitor circuits, but the actual RF signal being sent to the antenna.
Ability to hear the transmitted RF signal let amateurs identify and solve common problems, often without putting poor (or illegal) signals on the air. Hum, overdrive, distortion, RFI, off-frequency transmission, key clicks, excessive bandwidth, poor sideband or carrier suppression are some of the things we would diagnose in the shack with a live receiver. Of course it was invaluable in trying out different microphones and audio settings. Today with nothing but a transceiver we assume everything is okay and rely on other amateurs to point out glitches in our signal. In this respect transceivers destroyed a great big chunk of radio art making us oblivious to the one signal we should know the most about, our own.
I use a second transceiver as the station monitor. With a few clip leads at the antenna input, the second receiver picks up enough of the transmitted signal for evaluation of what I'm putting on the air.
73, Mike W8MW
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RE: Separate Transmitters & Receivers?
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by AE4X on March 15, 2004
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W8MW touches on some good points. Didn't think of these. As a matter of convenience having two "boxes" is a little bit of a burden. Been there--done that with the SB300/SB400 Heathkit. Never enjoyed it too much. But, as W8MW discusses, having a separate station monitor makes sense.
Having a RCVR and XMTR separate does, in some ways, make sense. Overall, though, I love having one radio to work with. 73.
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by KV4BL on March 15, 2004
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Interesting thread, to say the least. When I had my first ham license back in the early 70s (WN4BLV) as a Novice, I was forced to operate separate transmitter and receiver due to both economics and state of the art at the time. While there were transceivers made at the time, they were ususally prohibitively expensive and/or had some bugs with regard to getting your CW (or SSB for that matter) set on different frequencies if a split was necessary for some reason, such as operating near a band edge and communicating with someone in a country who's frequency and bandplan setups differed from yours. As an impatient youth struggling to increase my code speed to 13wpm (didn't really achieve that till years later in 1999) it was occasionally refreshing to work someone who was either on my frequency or quite a few khz away who could talk to me on SSB and I could send to him in CW. I found it much easier to send and could send far faster than I could copy. It was always a some time and fleeting pleasure but it sort of gave a brief feeling of what it would one day feel like to operate SSB with the "real" hams. Any way, my separate xmtr and receiver were good for that. I started out with a Heathkit (DX60B, I believe) AM and CW transmitter and an old Hallicrafters receiver I had saved up for and bought from a good friend. The Hallicrafters was a tube type general coverage receiver and was great for SWL and stuff but when I started seriously using it to make contacts, its shortcomings became obvious. When my mother would iron clothes, any time she turned on the iron or its built in thermostat caused its elements to heat up, it would draw current from the house's electrical supply. The lights would dim slightly and it was no big deal usually, but if I was in the middle of copying CW from some new and exotic (hey, back then, Canada was exotic to me) place, when the iron kicked in, my receiver would shift a KHz or two or more. Talk about destroying your concentration!!! Then, when the iron went off (usually immediately after a lot of hollering on my part when Mom came to see what the commotion was about) the receive would shift back a KHz or two or more to approximately where it was a minute or so earlier. I discussed this situation with a couple of my Elmers and other friends and the consensus was that a new and better receiver would clear up the problem. Not having the money to make this happen in the forseeable future, Mom, in her infinite compassion, love, and helpfulness, helped me work out a trade with one of the many companies which would do trades with you back then and pay the remainder for a brand new Drake 2-C receiver. It wasn't general coverage, but what it lost in other things, it sure made up with performance on the ham bands!!!!! This receiver didn't recognize voltage drops (or increases). The lights could dim significantly when the old window AC unit kicked on and the signal didn't change a bit! It was more selective with filters and it had hybrid (tube and transistor) circuitry. My point here, is that I couldn't have afforded to replace a transmitter AND receiver or a transceiver but the receiver was barely within reach of our ability at the time. I had an old relay box that came with the transmitter (purchased from another ham friend by my paternal grandparents as a Christmas gift for getting my Novice license) which I had to manually flip a toggle switch on each time I shifted use from the transmitter to the receiver. This was fine for a kid learning CW proficiency but would put a real cramp in a modern QSO on any mode. Also, after the FCC gave us Novices VFO capability, the "spot" switch on the VFO never seemed to have enough output for me to line up my xmit and receive frequencies to my satisfaction. On some bands, if the noise level was up just the least, I couldn't use thd spot switch as I couldn't hear the signal or get an S reading. Guess the point I am trying to make is that at that time in life, the separate transmitters and receiver
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by KV4BL on March 15, 2004
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....got chopped off....page 2.. ...worked fine for me. Now, with modern technology and the state of the art being what it is, I generally prefer the transceiver but have hopes of one day getting the old Heathkit and Drake fixed up and back on the air. Don't know if it'll actuall ever happen but I can hope. I was intrigued by a couple of the posts regarding using separate Icom radio and having them "track" together. Neat combination of nostalgia and modern technology! 73, Ray KV4BL
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RE: Separate Transmitters & Receivers?
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by WB2WIK on March 15, 2004
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A transceiver is a less costly, more efficient use of space. Using a common frequency generation/tuning scheme, power supply and other components, it costs less to manufacture a transceiver than it does a separate transmitter and receiver, and the resulting product occupies less space.
Seems pretty simple to me!
WB2WIK/6
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Separate Transmitters & Receivers?
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by G0GQK on March 15, 2004
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I rather think that creating a modern production line for the manufacture of what you envisage would be the quickest way to bankruptcy. One of the big three has enough problems to contend with at the moment in correcting poor quality tranceivers without even considering manufacturing "turkeys".
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Separate Transmitters & Receivers?
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by K0RGR on March 15, 2004
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I always thought that separates had one minor advantage for CW because I could directly hear what frequency I was on vs. the other station without having to guess the offset. When doing 'hunt and pounce' DXing or contesting, you could zero-beat the last guy the DX worked real easily. The transceiver wins hands down for SSB and rapid QSY situations, though.
I don't care much about the desk space. Actually , I find that the smaller XCVRs lead me to think that I can squeeze my whole station into a very small corner, and the fact is, it gets claustrophobic at times. You could argue that more space is needed for computers and monitors these days, I guess.
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Separate Transmitters & Receivers?
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by G3VGR on March 15, 2004
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What I believe has compromised performance is when the manufacturers decided to add general-coverage receiver functionality to ham bands only transceivers, resulting in poor RX frontend performance. I would rather we had hamband only transceivers (like the K2)with decent selective bandpass filters for each band, then use a separate GC receiver for SWLing & monitoring.
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RE: Separate Transmitters & Receivers?
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by K2WH on March 15, 2004
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There already is! It's a Hallicrafters HT-37 and a Hallicrafters SX-111. Then you can add the HA-1 keyer and then the R-46 seperate speaker.
See, it's all there and nothing new.
K2WH
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RE: Separate Transmitters & Receivers?
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by W0IMO on March 15, 2004
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I got my first ticket over 50 years ago. I have never owned a transceiver. They have their advantages, I am sure, but there are some compromises.
I have used a lot of old boat anchors and home made stuff over the years. For the last 25 years or so , I have been using Drake C line twins. I have a 600 hertz roofing filter in the the front end and 125 hertz filter,250 and 500 hertz in the last IF. I have all the selectivity, I can use. In fact some DX stations are not stable enough to stay in the passband when the sharp filters are in. I know it is not my receiver drifting, because I have checked that many times. Along with the great selectvity, I also have plenty of sensitivity. I also have a Drake L-4B Linear which I seldom use, because it is not needed. I have not had the thing on in several years. I guess the one thing I am giving up is QSK, but I am working on that, and if needed, I an live without. I work CW only so I do not need all the fancy audio enhancements available in the modern transmitters.
There may be a lot of new stuff that is better than what I am using, but I can live without it. I also can get along fine without digital readout. I do not see the need to spend more money when I am satisfied with what I have.
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RE: Separate Transmitters & Receivers?
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by RobertKoernerExAE7G on March 15, 2004
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A few years ago, when I was talking with Kenwood about the advantages of a transmitter with a receiver designed for the low bands, accompanied by a receiver designed for HF bands, their response was that there isn’t enough demand for even a transmitter-receiver combo.
Seems simple enough; no demand, no product offered.
Bob
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RE: Separate Transmitters & Receivers?
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by WB4QNG on March 15, 2004
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Ease of operation, size, cost. That would be my guess. I must admit though having twins, an amp. an antenna tuner, watt meter, a scope and a phone patch all on your desk sure looked good. Of course you had to have a desk as big as a kitchen table to hold it all. I know when I had all my old tube equipment I built a 10X3 bench to hold it all. Now it all fits on a computer desk and I have added a laptop to go with it.
Terry
WB4QNG
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RE: Separate Transmitters & Receivers?
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by WB4QNG on March 15, 2004
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One more thing. I think that the fact that modern transcievers have dual VFO's in them makes twins less attractive. In a way you have two radio's in one. Have a question for the man with the Icoms. You really think the reciever in the R75 is that much better than the one in the IC718. I thought the R75 was the IC718 with out the transmitter. I bet they do look good together.
Terry
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RE: Separate Transmitters & Receivers?
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by KQ6Q on March 15, 2004
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AM or CW transmitters had circuits nothing like receivers. SSB transmitters were a lot like receivers, so it was logical to save on parts, and combine the functions into a transceiver. Logical in the 50's (the KWM-1 was the first), still logical now.
I improvised a transceiver back in the late 50's as a teenage General. My HRO Sr was disassembled for modification, and one of the bands was wide open (probably 10 meters), and I still had my original knight Ocean Hopper rx, and my Heath VF-1 and Knight T-50 were operational. The antenna relay I'd built into the T-50 had some capacitive coupling on 10 Meters. Put my T/R switch to T (keyed the VFO, put the ant relay on transmit) I tuned the Ocean Hopper to just below oscillation, put the VF-1 on spot, and used the VFO as a tuneable BFO (direct conversion here), worked full-break-in transceive with a total of 5 tubes (two in the Ocean hopper, one in the VF-1, two in the T-50 - not counting rectifiers and voltage regulator). Made some fun contacts. Got the HRO back together later, had great time, but it took up more space that my ham station and two PCs do now - Big rx box, separate rack of plug-in coils, 12" external speaker in metal case, and external power supply. Transceivers are nice!
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RE: Separate Transmitters & Receivers?
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by KL7IPV on March 16, 2004
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I find it easier to put a transceiver in my vehicle than separate units. And I like the smaller size of a single unit for most things including the desk space I recovered.
73
Frank
KL7IPV
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Separate Transmitters & Receivers?
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by WA2JJH on March 16, 2004
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You can use 2 TS-850's or two TS-870's, if you want the cool look. A simple cable does it.
It seems we voted with our dollars. The SHACK IN A BOX design was simply cheaper. A performance compromise, yes!
IMHO, when the Yeasu FT-101 and the Kenwood TS-520 came out, that sealed the deal for a shack in a box!
I have never Met an unhappy owner of a collins S line or Drake C line.
I just got a used Drake TR-7. Love the rig. However I would really like to get the matching R-7A!
The R7A is a top notch RX. I feel a little riped off that my TR-7 does not have that great drake notch control.
R7A's are seldom sold. If there was one for sale, it would command an ultra high price! The R7A had a mil variant. No PTO. digital VFO. MIL SPEC. Their was also
a mil spec variant of the TR-7. Digital VFO. Hook them up. A mil spec solid state C line. Thats top shelf, even though the rigs are over 20 years old!
Sure, you will see an inferior extra RX built into a transceiever.
Some like seperates because it looks cool, as another poster said. Some will say seperates give them an edge in hard core contesting and DX chasing.
The TR-7 does have an external RX input. Will I try to make an interface to make them work like a C line.......Nah!
Then again who knows! Icom comes out with the 7800.
10 grand for a rig?
Wish they made a companion RX for a Harris 350.
That would be my DREAM shack!
For $600-$700 back in 1975, a TX, RX, PS, and speaker in one box seemed to sweep the ham community.
So "shack in a box" (TS-520, FT-101) allowed many hams to have 100W and 10-80M coverage for a decent price. However at that time, if you had the bux and wanted superior performance............Drake C line!
73 MIKE
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by W8KX on March 16, 2004
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Separates harken back to the day when there were manufacturers who specilized in building communications components. For example Johnson specifically made transmitters and Hammarlund and National specialized mostly with receivers (although later blurred). Also in those days it wasn't as important with AM and crystal control to net precisely the transmit and receive frequencies that one used. In many cases the poor selectivity of lower end receivers made the point moot.
The main advantage of a transceiver relates to it's ability to precisely net the transmit and receive frequency. This is important for SSB and their popularity correlates precisely with the advent of SSB on the bands. It was a great operator convenience to have your equipment transmitting and receiving precisely on the same frequency and absolutely necessary while mobile.
I would question wether much would be gained from a performance perspective by going to separates relative to the high end transceivers currently available. Certainly a case could be made from the marketing view though, especially if some standard could be agreed on to permit interoperation. Small transmitters and receivers built to something like, say an IC-706 footprint would be kinda cute.
W8KX
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RE: Separate Transmitters & Receivers?
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by W2DUG on March 16, 2004
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> I'm glad to see this thread because I have been considering using my
> Icom 756 and Icom 706 in tandem with one acting as receiver and the other as transmitter.
> As the previous poster stated it's very easy to connect the rigs together
> via a simple cable and have them both track the same frequency and mode when
> the controls on one radio are used.
Here's an opportunity to elmer a low-life no-code Tech: In this example, what would be the advantages? With such full-featured rigs, this seems awfully redundant. Help me see the light.
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by NQ5T on March 16, 2004
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I think the modern transceiver -- particularly those with most functions implemented in DSP (Orion, 7800, and surely others)-- are in fact effectively separates. They just happen to have everything in a single box.
From a performance point of view, there is little if anything to be gained other than the added expense of packaging in separate boxes, the additional control features that would be required to enable cross platform control and transceive when it was desired, etc.
There was certainly a time when most transceivers represented compromise, particularly in the receive chain. The current crop of modern radios doesn't suffer from from that downside. While it might look good on the desk (hey, the Gold Dust Twins are certainly impressive LOOKING), I don't see much to be gained in any practical way.
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by WA2JJH on March 16, 2004
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W2DUG, there are a few reasons.
Some of the reasons are good and some do it just because people like to experiment.
1)Practical example. You have 2 transceivers. One of the rigs are known for it's superior sensitive receiver, with lots of filters in it. (either dual stage IF or IF DSP with roofing filter.
The other rig has a medeocre RX. Many of your mobile DC-daylight rigs simply do not have a good RX on HF.
The other rig for TX may have a RF speech proc in it.
So by matching the rigs up as a system, You will have great TX and RX.
A popular config. like this is a Kenwood TS-870 and TS-850.
The 870 cost $1800 and is new and DSP. you can pick up a used TS-850 for $700. Many do not like the autonotch on the TS-870. The TS-850 has no DSP, however
this rig has twin stage 8 pole XTAL filters and a manual notch. Many like the twin analog passband tuning.
You also can just use the TS-870 for transceiving. Then use the TS-850 for finding DX on a different band.
This combo gives you an excellent reciever of a fully XTALED TS-850. With the excellent DSP transmitter of the TS-870.
Yeah, some just do it because the compexity is cool!
If you work ham satellites you need seperates to0.
One rig to input and hopfully saturate(good signal) the transponder. The other rig for the return RX.
Some rigs make it easy to tandem. Others are stand alone.
Some do it because they like operating old fashioned style. Drakes and the expensive Collins rigs are the prefered choice for tandum tube rig stations.
Another example. One rig is better at driving your tube amplifier to legal max(1500 PEP). The other rig has the really good RX design.
One rig has a dead transmitter section. Use it as a rig to tune around 20 meters. Your working 40M on another rig. You hear some DX on the dead transmitter rig. Tune the good rig to 20M.
These are just some reasons.
Technology has changed. A transciever was a compromise. No more!
Today one would have to buy a Harris, Racal, or other commercial/militry recerver to notice.
to notice any difference.
Some hams just like to be surrounded by radio's. Nothing wrong with that.(as long as your feeding you kids and not going ito debt)
Some tandem rigs, because they can!
73 MIKE
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by WM5Z on March 16, 2004
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In days gone by, it was near imposible to think of operating without split transmitters/receiver combinations. There were few "transcievers" on the market.
If true seperate operation is wanted, and I see no performance gain in doing so, you should consider a rig such as the FT-1000MP Mark V. This appliance has all of the features that one would want to entertain that seperates offer, but with true transcieve capabilities as well. It would also give you several added features that would not be available with seperates or "twins", like two receivers. I think that these added features well make up for the inconveniences of extra cables, extra desk space, lack of mobility/portability and the chances of mistakenly operating accross 2 bands! Me personally? I wouldn't give up my transciever for twins for anything.
Steve Friis/ WM5Z
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Separate Transmitters & Receivers?
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by WIRELESS on March 16, 2004
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I think the question now should be are 2 transceivers linked together better than a separate T and R? I use 2 IC706's together and the convenience having 2 transmitters and 2 receivers that can be linked or separated can do some tasks that really need to be analyzed to see the possibilities.
Split frequency between HF and VHF or VHF and VHF are pretty unique capabilities. Try it if you have 2 Icom transceivers.
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by N9DG on March 16, 2004
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Why think so small? If only radios were built with Ethernet interfaces, the receivers, transmitters, control panels, control PC's could all interconnect with each other with ease. The "black box" radio backends could be easily remoted a few feet or many miles away if you wanted to do so. They could easily integrate with the Internet (via Echolink et al.) if you wanted to (or not if you don't). They could tie V/UHF to HF easily for remote base operating. You could drive all the radios with one control panel or the same radio from several different control panels in different locations. Or add 2, 3, 4 or more receivers if you wanted. Mix and match and add components to your hearts content to build your station with the specific capabilities that you want, not what the radio manufacturer’s product managers tell you that you should want. So yes separates are a perfectly fine idea as soon as hams in general get over the notion that radios must/can only be a "station in a single box" with lotsa knobs/buttons and lights. The basic separate RX/TX combo of yesteryear is however kinda limiting. It also goes without saying that top-notch RF performance is a requirement as well.
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Separate Transmitters & Receivers?
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by KE2IV on March 17, 2004
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I guess this is the retro of ham radio.
Forget the technology and all that jazz.
This dude want to bring back "Twins".
I'll bet he's been reading CQ Magazine and wonders if we can get rid of solid state too?
Actually, on a nostalgia kick - I bought a Kenwood 599 pair a couple of years ago.
So what? Nice to play with but not nearly as good as today's rigs!
Oh, and I also bought a R-820 (now there's rare one) which CAN be "twinned" to the TS-820 with some "circutry surgery".
Anyone interested in buying any of this stuff should e-mail me.
Oh, that that guy who wants to "twin" his IC756 with the IC706.
A simple question, just like the one that the doctor at the "nice hospital" will ask:
"Why?"
FOR CRIPES SAKES...TALK ABOUT WORTHLESS THREADS...WHY DON'T WE JUST GO BACK TO SPARK?
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RE: Separate Transmitters & Receivers?
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by K3BU on March 17, 2004
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KE2IV screamed:
>>"Why?"
FOR CRIPES SAKES...TALK ABOUT WORTHLESS THREADS...WHY DON'T WE JUST GO BACK TO SPARK? <<
Looks like here comes one of those who know everything, "knows" what is worthy and worthless and tells the rest of us what to do :-)
There is a need for separates any time you want or need to transmit and receive at the same time (same or different frequencies), like contesters, VHFers or anyone who has a need or imagination. Last time I have done it was with Drake "trins" - two receivers and one TX. Allows you to tune the band(s) while transmitting. It is also done with two transceivers or ganged receiver, as it was described earlier. I appreciate the feature for contesting and verifying how my signal sounds after going through the whole chain, including amplifier.
New upcoming Computeradio DR1 radio will have high quality separates, in one box, smaller than some less worthy transceivers. It will have flexibility and programmability that will open doors to those who will appreciate it. Sorry, no spark TX.
Live and learn, Eh?
Yuri, K3BU
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Separate Transmitters & Receivers?
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by KX2S on March 17, 2004
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Remember when Japanese tranceivers first came out. I think the term was "rice box". Ran an HT73 and Drake 2A for many years. Would never consider going back except for a retro station. Also how many remember when SSB started showing up on the bands. That will never get anywhere. They sound like a bunch of "Donald Ducks". Guess for oldtimers it's been there done that.
73 Ed
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RE: Separate Transmitters & Receivers?
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by KB7YOU on March 18, 2004
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Hi KE2IV,
I want to use my 706 and 756 together for cross mode work, "triple" watch and satellite work. Oh yeah, one more reason - the radios can do it so I'm curious to see what I can do with the feature. Might come in handy, might be worthless. Will not know till I try.
Nothing retro here.
So my question still stands - is there a problem with potential damage to the RX radio when transmitting on or near it's frequency when the 2 antennas are only a few feet apart?
Chris
KB7YOU
" Oh, that that guy who wants to "twin" his IC756 with the IC706. "
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RE: Separate Transmitters & Receivers?
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by KA4KOE on March 18, 2004
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YOU:
There is a definite and very real possibility of frying the front end of the receiver, particularly if it uses sensitive components (almost assuredly). You (YOU) could probably get away with it with tubes, but not solid state.
I had a radio receiver on a separate antenna on standby on the 80 m band. The induced voltage smoked a resistor inside the receiver.
Given the value of the 756PRO and the 706, I wouldn't chance it.
PHILIP
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RE: Separate Transmitters & Receivers?
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by W6TH on March 18, 2004
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I do have a ICOM transceiver, but most of my fun come with the Viking Challenger transmitter at 75 watts output and no tuner needed and the HQ 120 Hamarlund receiver. Receiver with my beverage antenna and the Challenger with the Zepp antenna.
Works great as it did 52 years ago on 80/40 cw and the 75/40 AM bands.
Oh! By the way, I do my own repairs, but no breakdown for the past 45 years, seems to run forever. WOW, the money I saved. I used the saved money to buy my ICOM.
.:
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Separate Transmitters & Receivers?
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by WA2JJH on March 18, 2004
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Yes, I should have said, one better know what they are doing, when tandeming. You can get 110V in your RF line.
Most of the newer rigs amkw a specific cable so one rig can control the other and vice-versa.
The reason why I brought up two TS-85O's is because there is a special cable that WILL make one rig all TX, the other All RX.
The TS-850, while from 1991, are better than some of the new rigs that sell f0r $2000. You can get them for about $800 bux or less. Put all the XTAL filters in the RX TS-850. The TX 850, Do all your fancy audio processing. Put in the TCXO for the 5 channels of 60meters ON THE tx.
I would love to see a side by side test with that $10,000 ICOM 7800. SEE HOW MUCH A NEW TEN THOUSAND DOLLAR RADIO, DO AGAINST $1600 IN RADIO'S!
I WOULD HAVE DESIGNED THE 7800 LIKE LEGO!
THE TX WOULD BE BLUE. THE RX WOULD BE RED! THE SNAP ON POWER SUPPLY WOULD BE BLACK!
THIS WAY, JUST WANT AN RX-USE THE RED HALF!
THE WHOLE STATION WOULD ASSEMBLE LIKE LEGO!!!!
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Separate Transmitters & Receivers?
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by WA2JJH on March 19, 2004
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Steve WB2WIK/6, I am asking you this one because we both own a TS-850SAT and a DRAKE TR-7. I have also seen some real creative solutions from you.
I would like to tandem operate my TS-850 and TR-7. I know I will have to build some custom interfaces. I would like to be able to avoid a PC interface.
Would it not be a hoot to use the TR-7 for it's 190W output for tansmit. I bought the external DRAKE RF speech proc, the sp-75.
I would use the Kenwoods Dual IF filters, dual passband, and maual notch for my RX. Have all the memories too.
I would love to see the high end pair, working as a system as my DREAMSHACK.
I just ordered a HARRIS 350. That rig has rs-232. It might be easier to tandem tht rig. Just a thought!
73 MIKE WA2JJH DE NYC
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RE: Separate Transmitters & Receivers?
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by K6TLA on March 19, 2004
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Someone else called this a worthless thread...agreed.
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RE: Separate Transmitters & Receivers?
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by KD2E on March 19, 2004
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To George (KE2IV)
Say, would you happen to have that R820 to TS820 link cable???
...Dave
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RE: Separate Transmitters & Receivers?
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by K8VF on March 20, 2004
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How much for the ts820 and R820?
I am interested.
Your email address is not available to me.
Mark.
ae8844@wayne.edu
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Separate Transmitters & Receivers?
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by N8FVJ on March 21, 2004
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Too expensive. Two 'boxes' cost more than one & it is not just what's inside.
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Separate Transmitters & Receivers?
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by WA2JJH on March 22, 2004
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For some it is just nostolgia. Certain TX's+RX's are like ham and cheese. Like the Drake C line, Collins S line.
One combo that did not work was the DRAKE TR-7/R-7.
Drake left out a notch fruction on the TR-7 transceiver. The R-7 had the notch function and a few extra RX features like a pre-amp.
Very few R-7's are around. Not too many produced.
By 1980 the "shack in a box" concept was just too much competition. The 'shack in a box' would cost almost half price as seperates.
The only external RX some may buy these days are a mil. spec Racal for better general coverage.
While the transceiver design no longer has compromises on the ham bands, they are a medocre substitute for a world class RX for non amatuer bands.
I personaly like the 'shack in a box' like most hams.
However you will never change a Drake or Collins hams
opinion.
I did bid on a Drake R-8, However I did my research. The R8 is no R7!
I keep my eyes open for a modern RACAL for a good price. I am not holding my breath!
Some peoples shacks have many rigs in them. One dude had 3 Drake C lines and other rigs in his photo. Maybe all the tubes heat the shack!
I am still looking for a decent RACAL RX. Will I use it with my transceivers.....NO!
The only reason I could think of having seperates is if you have to send out the TX or RX for repair. You could make due with a cheap RX, if your rx is at the shop for repair. If your TX is out for repair, you can still listen????????
The only other reason are boatanchors. You may get an RX for $75 and an old CW/AM TX for $100. You have a station for $175 or much less. Some Ham did get a TX and RX at DAYTON. Total cost......$85! His budget was under $150. No cheap TS-520's that year.
73 MIKE
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Separate Transmitters & Receivers?
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by N2EY on March 22, 2004
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It's all about cost and size. HF ham transceivers were developed more than 40 years ago (Collins KWM-1, KWM-2, Cosmophone 35, etc.) to reduce the cost and size/weight of an SSB ham rig. Early HF ham transceivers sacrificed some features and performance to gain the smaller size/weight and cost. But as the technology developed, the differences were greatly reduced.
For example, most early transceivers did not offer split operation, AM, QSK, defeatable AGC or filtering options. Now almost all of those features have made their way into even entry-level ham transceivers.
Look up the prices of an S-line, Drake-line or SB-line and compare the cost of separates with the transceiver by the same manufacturer.
The one *big* advantage of separates, even today, is that they are easier to build and work on.
73 de Jim, N2EY
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RE: Separate Transmitters & Receivers? - some
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by NJ0E on March 23, 2004
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separates made alot of sense when manufacturers were
specialists; national and hammarlund for receivers,
viking, eico, globe (wrl) transmitters (and many
others).
separates also were not difficult to use in an era
when the average qso lasted much longer, sometimes
many hours. am enthusiasts continue to practice this
type of activity, but it used to be alot more common
than it is today.
in today's "hunt and pounce" contesting/dxing type
operation, the transceiver is much easier to use
with just one tuning knob.
it's also easier, i think, to implement full breakin,
(qsk), in a transceiver. i operate cw 99%, and have
become very addicted to full qsk (as ten-tec
implements it); i just don't like the chattering relay..
some newer transceivers have dual vfo's, or even an
entire second receiver built in (the ten-tec orion
has a primary "ham band only" receiver, with it's
advantages,plus a sub-receiver that is general
coverage, built in to one box).
some qrpers still use separates also; they may build
a kit receiver such as the ten-tec t-kit 1056, and
use it in conjunction with a variety of experimental,
homebrew transmitters.
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RE: Separate Transmitters & Receivers?
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by N7DC on March 24, 2004
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It amazes me tht half way down into the many messages, people are still complaining about the subject. Why read that far, if you think so?
Now as to the subject: Only those who have experienced the exceptional capability of running two separates will appreciate the question. Yes I am one. The last separates I bought were the Yaesu FL?FRDX400 line. Excellent 200 watt rig, with a pretty hot receiver. I could listen to the split band at the same time I listened to the DX station who was calling. Great stuff that.
Someone asked about using a second receiver with a separate antenna just a few feet away from his transmit antennas. DONT DO IT. Eventually (Im supprised it hasnt already happened) you will burn out the receivers front end. TOO MUCH POWER and too close to the antenna. Find a way to mute the receiver while the other transmitter is transmittting. Pin diode may do it.
This subject has decided me on something I recently had a passing thought on. Im getting out the old TS430s whose transmit has bit the dust. It will become my new separate receiver, to use with the newer TS570s. I think the 430s receiver is better anyway, or at least a more comfortable audio output level I can hear. Both have 250 cy CW filters. The 570 of course has audio DSP where the 430 doesnt, but we shall see how this works.
Anyone have experience doing that? Some of the former notes in this forum say they have done similar. Any hints as to how to start?
Danny
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Separate Transmitters & Receivers?
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by W3DCG on March 24, 2004
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Well...
I like the idea of having a separate RX to check how my signal sounds; but now days, with costs the way they are, I have that, it's simply my other RX is a transceiver, so it can transmit, too.
Actually, I find it easier, to press one button (the one that toggles SPLIT) on and off, if I want to transmit on my RX frequency.
I think it's a matter of technology having advanced to the point whereby, excellent Rx and Tx performance was to be achieved in one box.
In the current age, I'd prefer two transceivers over a separate Tx Rx arrangement, especially since even the lowest cost new radio performs such function admirably, compared to 30 years ago. Low end transceivers of today and even 80s era, probably perform at least as good in both the transmit and receive arenas.
One may argue that nothing produces sweet mellow voice audio better than old tube gear, and I'm not one to disagree, as the sweetest voice audio I've heard has come from hybrid TRANSCEIVERS, such as the TS 530, 830, and FT 990.
Which is not to say, that Collins, Drakes, Swans, don't sound great either. But the audio standouts I have noticed, come from the three previously mentioned- not counting, the Hi Fi people with all the extra processing, pre-amp, and equalizing gear, all those hundreds, thousands of dollars invested in microphone (s)and audio processing gear, piped into the computer for spectral analysis, or at least a separate scope. Undoubtedly, those people sound both broadcast quality and blown-speaker quality, depending on how they choose to sound.
No, I'm refering to the average Joe, talking with his one or two transceivers on the desk, with an old used microphone, sometimes hand-mic, sounding relatively phenomenal, with no processing, not even an IHY box, sounding very good, very clean, with an old TS 530!
With such choices, I don't miss the nostalgia of stand-alone TX RX at all.
I would have had tons more fun, when, as a child blessed with a flea-market T150A/SX99/straight key combination, if it instead would have been an expensive modern transceiver (like a TS 520/FT 101 or Triton IV) remote VFO, and ANY electronic keyer. hi.
The Kenwood Twins were a marvel to look at, I remember about 600 bux each, the Drake twins were similarly marvelous, no? Not sexy looking though.
No, I rather not go back to those dream stations...
I prefer transceivers now, given what they have to offer- which is everything I want, and more.
It may even be a popular opinion, evidenced by current market offerings now, and over the past 25 years.
73.
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Separate Transmitters & Receivers?
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by N6AOT on March 25, 2004
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Larger radios =
... more room for shielding in RX case;
... room for PS in TX case;
... fewer osc's in each box - fewer birdies???
... more spacious front panel surface areas for
controls, avoids "menu" style of control.
Unforutnately most hams are feature-vs-size crazy, sometimes small size is a necessity. And it wouldn't be price competetive against a single-box transceiver -quite a bit higher price for small performance increment...
But nice to think about...
73 de Bill N6AOT
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Separate Transmitters & Receivers?
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by WB9AUJ on March 28, 2004
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Guess I have the "best of both worlds". Use the "C" line pair for PSK-31 and have a Hallicrafters SR-2000 for back up on SSB / CW. "If it don't glow, it ain't got guts".
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RE: Separate Transmitters & Receivers?
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by K3UOD on November 29, 2004
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With my Drake B line, if I wanted to switch from 75M to 20M, I would:
-change the band switch on the R4B
-peak the preselector
-tune to the desired freq
-change the band switch on the T4XB
-tune to the desired freq
-set the mode switch to TUNE
-peak the drive control
-dip the plate
-peak the load
-dip the plate again
-peak the load again
-re-peak the drive
-switch the mode switch to STANDBY and let the sweep tubes cool down
-switch to TUNE again and dip the plate one more time
-switch to LSB and start operating
Of course, If I wanted to operate on a WARC band, I had to switch in the proper accessory crystal.
With my FT1000 MP MK V Field, to switch from 75M to 40M, I push the "7.0" button. Then operate.
I don't miss the TX4B at all. I do miss the AGC and notch filter on the R4B.
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Separate Transmitters & Receivers?
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by WA2JJH on February 22, 2005
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It can make sense again, belive it or not. N4PY has software that lets control two rigs.
I now have a K2. The RX is as good as people are saying. Very unique engineering. However it is 15W out max.
I purchased a used broken pegasus.I did a few minor repairs. The Pegagas has a so-so RX. However it is a full 100+W TX with a superior speech proc than the K2.
So when I want 100w or drive my hl-2200 amp, I can use the pegasus for TX, then use the K2 for it's great
RX.
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RE: Separate Transmitters & Receivers?
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by N8CPA on July 3, 2005
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I don't know about separate RCV/XMT rigs. I used such a system with a homebrew transmitter and a shortwave receiver 20+ years ago. In my case it was a pain! The only benefit was that I learned to read code through nearly unsortable QRM, due to the receiver's lack of selectivity. But I am currently working on a project to add vertical transmit and horizontal receiving antenna capability, like another poster indicated.
My IC-735 came equipped for such an arragnement. And during FD, I experimented by connecting an A/B swtich between the ANT OUT and RX IN jacks via short, shielded cables. What a difference! The A/B switch will keep the option of using the same antenna for both functions if directivity is an issue.
Oh no! Another antenna project! I'm so depressed! (Just kidding, of course. I'm a ham, after all)
Steve
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RE: Separate Transmitters & Receivers?
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by KG5LN on September 15, 2005
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What is the Icom part number for the cable between the receiver and transmitter? What jacks do you connect the mute line on the receiver & Tx?
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RE: Separate Transmitters & Receivers?
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by KG5LN on September 15, 2005
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What is the Icom part number for the cable between the receiver and transmitter? What jacks do you connect the mute line on the receiver & Tx? I will be using a R-75 and a 706.
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