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Author Topic: Premium Receivers.  (Read 14836 times)
AH6GI
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Posts: 60




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« on: February 15, 2010, 07:46:07 AM »

About Premium Receivers.

Over the years, I've looked at premium receivers.  I remember hearing about the R/390A in the 1960's.  Hams would speak of it with hushed, reverent terms.

From time to time, I've bid on premium receivers on eBay but I've never come close to winning any.  I've followed the discussions on the Internet on premium receivers.


The 851S1, used, is way up there.  So are Watkins-Johnsons, and the Ten-Tec RX-340.  The RX-340 is one beautiful receiver.  

<http://www.eham.net/reviews/detail/3757>

Recently I found the DZ Sienna, a premium receiver kit and a ham transceiver kit.

Comparing the Sienna and the Collins 851S-1 and the others, the Sienna has many more features, filters and more filters, and is amazingly configurable. It also comes with fancy, high-tech, mixers and amplifiers.

I am not a true believer of DSP and software filers.  I'm a software guy and my guess is that the way DZKIT cascades their hardware filters, builds a stronger brick wall.  


<http://www.dzkit.com/pdfs/DZKit_blockdiagram.pdf>

<http://www.collinsmuseum.com/851s1b.jpg>


I'd like to get a Sienna but am not certain how to configure it.  It comes with a 20 kHz roofing filter and DZKIT offers an optional 4.5 kHz 70 mHz roofing filter.  Will this constrain the AM audio?  The optional AM filter is 6 kHz.

I saw a comment on the Internet that DZKIT is shipping all receivers with the better roofing filter.

I was just about to order a basic Sienna but then it started snowing which affects my income.

Check out the Sienna and tell me how you would configure it.

de ah6gi/4 still digging out from the snow.
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AA4PB
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Posts: 12778




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« Reply #1 on: February 15, 2010, 07:58:56 AM »

I don't know anything about that radio, but anything that restricts the bandwidth to less than 6KHz has got to have a negative impact on the audio quality of an AM signal.
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K8AC
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Posts: 1465




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« Reply #2 on: February 16, 2010, 07:49:32 AM »

I was at the Orlando hamfest last weekend and had an opportunity to play around with the DZKit Sienna for a while.  I took a brochure with prices on it, and discovered that the price of the unit with a full complement of filters to compare with my other rigs drove up the price to a level where it would be hard to justify building the kit.  I was a bit surprised to find it was an up-converting design.  That pretty much rules out ever using a spectrum scope with it, and I think that's a required part of a modern state of the art unit.  My only experience with what are considered high-end receivers today was with the R/390A many years ago.  Before the sub-hobby of collecting ham gear began, you could pick up R/390As at a pretty good price and I bought three of them for $125 each from the SC National Guard, which was scrapping them back in the early 1970s.  I was able to make two very good ones out of the three and intended to use one as my CW receiver.  I quickly found it to be absolutely dreadful for that use, primarily because of resistance of the tuning knob (as you turn the knob, it's turning many shafts that drive cams).  You didn't say what use you intend to put a premium receiver to, but if you intend to use one on the ham bands, I'd advise trying it out before plunking down the price that folks want for them. 
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K1DA
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Posts: 481




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« Reply #3 on: February 17, 2010, 09:15:09 AM »

About the only radio I know of fitting that reqirement would be an R4C with the Sherwood mods.   I have one and it is a great cw unit.  There are, of course,  very good receiver sections in new
radios such as the K3, but in terms of stand alone
receivers which might not break the bank, that, and perhaps the later R7 are the only two I can suggest.
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N1KPR
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« Reply #4 on: February 17, 2010, 04:37:29 PM »

Although you didn't mention what your primary interest is, I would suggest that you won't be happy with a less-than 5 or 6 KHz bandpass for AM reception. Of course it's all about filter skirt aspect ratio (6/60dB) and ultimate rejection, and noise floor, and MDS, etc; but I find that for AM QSO's and general SWLing of the AM b'cast band and International shortwave b'cast listening, that 6 KHz is fine, provided that a nice tight filter is being used. I have no personal experience with that kit, but did talk to someone once who absolutely loved it.
But your post is titled "Premium Receivers" so I'm guessing you want to do a lot of SWLing. If that's the case, then the field opens up for you to select from. I have several Watkins-Johnson, Racal, ITT Mackay and JRC receivers, amongst other Collins, Kenwood and Icom stuff and can testify to the use of a good 5 or 6 KHz filter for general AM work. Some of the SDR offerings are not bad when considering the bang for the buck; a la Icom's various black boxes for general use and particularly the Winradio G303e and G313e if you are more serious about flexibility and features. A good test as to what filtering you may want/need is if you find someone with a JRC NRD-545 and play with the very wide selection of bandwidths.
Additionally, there are quite a few Maritime/government/embassy-type receivers too, which show up on Internet auctions and classifieds, and are usually reasonably priced. Of course, those are not DSP (usually) or SDR's. But the beauty of buying a 15 or 20-year-old radio like that is that you'll probably pay 10 to 15 cents on the dollar, of their original cost. Good luck in your search and please post back what you finally decide.
Bob, N1KPR <www.bobsamerica.com/swl.html>
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AH6GI
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Posts: 60




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« Reply #5 on: February 17, 2010, 05:03:00 PM »

K8AC, how did the Sienna seem to you?  Did you like it?

Was the tuning as smooth as the DZKIT site says?

I don't like digital read outs but the DZKIT site shows an LCD screen with a big analog tuning scale, reminds me of my old SX-101A.

I've been figuring out the filter options and find the options very confusing.  Some parts of the site imply that the 70 mHz roofing filter is a 6 pole 4 kHz INRAD.

That's great for CW and SSB but AM SWL, I'm not so sure about that.

Other parts of the site mention a 4 pole 15kHz "standard" roofing filter, which would be better for AM SWL work but not so good for CW and SSB in contest conditions, not that I do contests.

de ah6gi/4
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AH6GI
Member

Posts: 60




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« Reply #6 on: February 17, 2010, 05:37:16 PM »

Bob K1KPR,

For 45 years, I've wanted a "good" shortwave receiver.  My early ham operating was with an SX-101A, ham bands only.

Then I got a Heath SB-101, also ham bands only.  Going from Hallicrafters soft LC filtering to Heath's harder edged crystal filters was a big change.

About 1980, I broke down and bought an ICOM IC-720A, paid almost $2,000 for it with all the filters, the switching power supply, etc. I finally had my SWL receiver but work and life intervened and I didn't get my radio time.

I still have the 720A and do scan the bands with it. I have a collection of boat anchor rigs.  Some need  work, others are in near new condition.

While the 720A is plenty good enough for my SWL activity, I have the bug to get a real premium receiver, just once.  You know how it is.

Part of the fun is figuring out what the parameters are.  Then it's saving up the spare change or, more realistically, selling off some of the boat anchor herd to finance that one, last radio.

AM SWL listening is up there as a requirement.
Sienna has an optional $155 8 pole 6 kHz filter for 9 mHz.

CW too, that's a must have.  The Sienna has a $270 16 pole 400 Hz filter option.  It's two 8 pole 400 Hz filters.  One at 9 mHz and one at 455 kHz.

The other choice is a $155 8 pole 250 Hz filter at 455 kHz.  I suppose you could front it with half of the 400 Hz option.  Sometimes I like listening to CW with a wide passband, sometimes I like to tighten down.

I'm kinda indifferent to SSB, contest work, DX, so I don't need brick wall SSB filters.  However, I am interested in digital modes like PSK31.

The nice thing about the DZKIT Sienna is that I could start simple, add to the receiver, eventually turn it into a full transceiver.

If I got the contest bug, I could add more filters.

I've tried to map out the filter options on paper and there are so many choices.  It also looks like an incredible number of poles in the receiver chain, like 26 in some configurations.

This thing is all filters, amplifiers, and high-tech mixers.  I've never seen anything like it.

de ah6gi/4
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NO9E
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Posts: 391




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« Reply #7 on: February 18, 2010, 12:29:41 PM »

Not sure whether premium means "best receiver", best receiver with knobs.  

For "best" general receiver, I have been pleasantly surprised by SDR-IQ ($500). Perseus ($1100) is even better if not nearly perfect. But no knobs.

Ignacy, NO9E
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AH6GI
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Posts: 60




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« Reply #8 on: February 18, 2010, 04:35:36 PM »

from the QTH.net Premium Receiver list, the term refers to military, government general coverage, signal intercept HF receivers such as the R/390A, the Collins 851S-1, Watkins-Johnson, Racal, the Ten-Tec RX-340.  

Some models of DSP/SDR are certainly Premium Receivers.

Whether a specific radio is a Premium Receiver is one of those fun debates.

The Sherwood enhanced Drakes certainly qualify.  

I think part of it is the "look" and part is the "feel", that's in addition to the raw performance.

de ah6gi/4
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N7DM
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Posts: 671




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« Reply #9 on: February 20, 2010, 06:47:52 AM »

I was on active duty, shipboard, in 1959 and we put R-390's in Radio Central. Fabulously sensitive, possessing the [then new] Collins Mechanical IF filters. Alignment was not really difficult, but when you saw the number of gears to change Mega-Cycles, etc, it was a nightmare. Ever heard of an Intermittant Gear? One with teeth only a portion of it's circumference?

In the past twenty or so years I have kept an ICOM R-70 GC rcvr around. Great 'in the field' with my noise bridge, for antenna work, good for my 'listen to my own signal' CW monitoring, and a fine, sensitive, SELECTIVE, general purpose rcvr.

dm
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K8AC
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Posts: 1465




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« Reply #10 on: February 20, 2010, 03:34:54 PM »

To AH6GI:  The tuning on the Sienna was indeed very smooth.  I was a bit surprised at what a low profile the rig had.  The font they used on the display for the frequency readout is an odd one - reminds me of Times New Roman for printing.  Too much flare, I think, for the intended application.  The front panel is unlike any other on the market, and all the knobs are big enough to turn.  One that always gets me on the Japanese rigs - the CW keyer speed control - is a comfortable size on the Sienna.  On my Yaesu and Icom rigs, it's about the diameter of a lead pencil - too small to be of any real use.  I took the Sienna brochure back to the hotel with me and tried to figure out a total cost, equipped for CW operation.  I wasn't able to do that as I wasn't able to figure out all the filter options.  I do recall that it was above $3k, which I thought was rather steep for something you have to build yourself (and the build is considerably more complex and time consuming than the K3).
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AH6GI
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Posts: 60




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« Reply #11 on: February 21, 2010, 04:51:54 AM »

K8AC,

Thank you VERY much for your comments and your impressions on using the actual Sienna.  

I had noticed that the letters, especially the big numbers on the display seemed odd.  In my day job, I work on software and occasionally user interfaces.  I prefer sans serif fonts such as Verdana and Arial. I don't like little curlies on letters and numbers.

I'd prefer a half space between the mHz and the kHz or a larger 14 than the 235.

14 235.075  

These are not showstoppers for me.

Like you, I can't quite figure out the filter options.  I have a sheet of paper where I've written down the options.

Between the 70 mHz roofing filter which is described as 20 kHz, 4 kHz, or 4.5 kHz depending on where you look on the website, are 2 banks of 4 selectable filters.  One bank is at 9 mHz, the other is at 455 kHz.

I checked with DZKIT and the roofing filter is a nominal 4.5 kHz but the 6 db points are close to 5.0 kHz. This is good for AM work.

The Heathkit SB series had two different AM filters, 3.5 kHz and 5.0 kHz.  The 5.0 Heathkit filter is much sought after by AMers. It was standard on the SB-310 and SB-313.

There seem to be two 455 kHz filter points.  One point is selectable from the front panel. Following the four selectable 455 kHz filters is another position for either a 20 kHz ceramic filter (standard) or a 5.8 kHz Collins mechanical filter (optional).


I really like having all those options but I haven't quite figured out what they all are.

Since DZKIT is working with INRAD and the IF's are on standard frequencies, you could probably get anything you want from INRAD or someone on eBay.

One item I'm mulling over is the standard 70 mHz roofing filter for the FT-1000MP.  I found some websites that describe it as 12 kHz.  If it swaps in, then it might be better for AM SWL work.  12 kHz is wide but the AM SWL'ers seem to like wide AM mechanical filters on the Collins.

About the pizza box look.  I don't mind that.  I was about to order a Ten-Tec Argonaut V but Ten-Tec discontinued it.    The Argonaut V is as flat as they come.

The Sienna caught my eye because it looks like an Argonaut V all grown up with 10 times the features.

Both have real analog meters.  Both have quality general coverage receivers.  QSK, check.  The Argonaut V has a heavy metal main tuning knob as does the Sienna.  

When I saw the DZKIT Sienna ad in the December 2009 QST, I thought, WOW, here it is.

I'm still thinking this over. That's half the fun of a new rig. Checking out the options, knocking around the features with other hams.

One neat thing about the Sienna is that you can build and expand the basic radio.  There're reports on the web of hams doing exactly that.

<http://blog.g4ilo.com/2009/11/tempting-sienna.html>

<http://va3stl.wordpress.com/2008/07/09/the-sienna-a-new-high-performance-kit-hf-transceiver/#comments>

Start with a basic radio, build it up into exactly what you want.  You don't have to do it all at once.  The DZKIT site describes which filters snap in and which require a partial disassembly.

de ah6gi/4
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WB6VHK
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Posts: 189




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« Reply #12 on: February 24, 2010, 08:01:59 PM »

Just to let you all know, I have been using my Sienna for a few months now and it has to be one of the best receivers I have ever used. For now I only have the Inrad 70.455 roofing filter and the standard ssb filter. Last weekend on 20 meters I was I was comparing my new Harris RF-3200 ( just acquired on Ebay ) to the Sienna...embarrassing for the RF-3200. The Sienna has much better sensitivity and I could easily copy stations that I could barely hear on the Harris, even with only one of the two preamps turned on. I can't comment on the AM as I don't have the filters for it yet but it does not sound bad, even going through the SSB filter with the IF shift tweaked to the side a bit. It is not a inexpensive kit, I had to start off with the basic receiver and add the front panel and transmitter as my budget recovered but I feel it was a worthwhile investment. I think someone commented on the lcd display....It is not a lcd, I think it is a plasma. One of the nicest displays I have seen in a long time. ( I think it may be the same display used in the latest Cubic receivers ) ...73, Darrell / WB6VHK
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AH6GI
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Posts: 60




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« Reply #13 on: February 25, 2010, 03:48:04 AM »

Thanks Darrell,  your first hand, user experience is a great help.

DZKIT put up more info on their filters.  <http://dzkit.com/filters.htm>

I've always wanted a really good shortwave receiver.  

de ah6gi/4
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WB6VHK
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Posts: 189




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« Reply #14 on: February 25, 2010, 11:58:10 AM »

To correct what I wrote in my last comments, The display is a vacuum florescent display, not a plasma. Darrell / WB6VHK
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