The TR7 was a single conversion receiver and excellent in its time.
The TS-520 was pretty useless on the low bands, except for working stations
that were stronger than S9.
The Drake lines with Sherwood filter were the best thing going in the 70s.
The Atlas 180, 210x and 215x were considered to be as good as it gets for a
stock production radio.
Funny, I had always wanted an FT-101E which at that time was the berries!
Transistorized RX and 3 tubes in the TX line.
Being in the army, I couldn't afford one, so I bought the FT-200, which is
the same as the Henry Radio Tempo-One in the states. Turns out that it was
also a single conversion (down conversion) to 9 MHz and it out-performed the
FT-101E on the low bands. I added a CW filter and external home-brew
preselector had had a pretty good contest radio.
The TS-830 was not bad for its time.
The IC-730 and IC-740 were still downwards conversion and good for their
time periods.
All successive Icoms (until this day) were upwards conversion.
Icom still hasn't understood the problem.
However I must say that the problem on 40m is nowhere near as bad today as
it was 10 years ago before the broadcast stations moved outside our band.
One of the BIGGEST problems is, some crazy FOOL got the idea that our top of
the line transceivers also needed to work AM and FM. In order to do this,
it mandated an broad first filter in the receiver (6kHz for AM, 15 kHz for
FM). Today we call these first filters "roofing filters". A 6kHz filter at
9MHz does a fair job but at 45 or 70 MHz, it is pretty worthless. Skirts
are a mile wide.
We were able to fix this problem in many radios by adding a narrow Sherwood
or INRAD roofing filter, which meant you could no longer work AM or FM with
the radio. Ten-Tec was the first to solve that problem with its Orion by
giving us switchable roofing filters at 9 MHz (where they had decent narrow
skirts). An INRAD filter on an upwards conversion radio does help but not
nearly as much as one used on a downward conversion radio. Has to do with
the laws of physics (fractional bandwidth).
If we want to have a simple retro radio, like a Corsair III, and want to
keep it simple and cheap, then it will need to be single conversion with an
IF of about 5 MHz. These filters work even better than 9MHz filters. Of
course with single conversion, you can't have passband tuning. But cheap is
cheap.
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Dave
Edwards
Sent: Thursday, October 02, 2014 11:26 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Modern version of the Tec Tec Corsair - please Ten
Tec!
Rick...
How do some of the older rigs do in your situation.....an old TR7, a Kenwood
TS-520...can anything old survive, or must it be a current production rig to
fight off the muck??
....Dave
On 10/2/14, 2:48 PM, Rick - DJ0IP / NJ0IP wrote:
> Wade,
>
> I quit wearing the cape; no more phone booths here.
> They went away years ago.
>
> People who have never operated in Europe simply have no perception
> about how much worse condx are here on the low bands.
> It has gotten better since the broadcast stations on 40m moved up and
> out of our band, and they widened the band from 100 to 200 kHz.
>
> The problem most radios have here at night is with Intermodulation
> Distortion.
> We have a nice name for it in German. We call it "Wave Salad".
> It is basically an S5 to S9+30 noise level across the entire band,
> depending on which radio you have.
> The problem is front-end overload.
>
> The better the BDR3 is on the receiver, the lower this noise level will
be.
> Keep in mind that these are noises which are not really there.
> They are basically phantom signals caused by the front-end of the
> receivers overloading.
>
> In general (with extremely rare exceptions), radios with upward
> conversion have about 20dB worse BDR3 than radios with downward
conversion.
>
> To understand the magnitude of the problem, each dB improvement in
> BDR3 will reduce the IMD by about 3dB.
> So if I improve the RX front end by 20dB, it reduces the IMD by 60 dB,
> which means it pretty much disappears, except for a few exceptions.
>
> There are a couple of things you can do.
> First and foremost, use an attenuator.
> 10dB of attenuation will reduce IMD by 30dB.
> Of course if the station you wish to work is a weak DX in the Pacific
> and he is only S1 or S2, switching in 10dB or more attenuation drops
> him into the noise (the normal noise).
>
> Better is a good preselector. These typically have 6dB insertion loss
> but drop IMD by 30 or 40dB.
> This is the route I went prior to the Orion.
> The Orion was the first radio I ever operated in Europe that did not
> need a pre-selector.
> I never experienced intermod on it except when operating with a 3
> element yagi on 40m and pointing the antenna N-NE.
> In that case I could hear a few phantoms at about S2 or so.
>
> In the meantime there are several radios that are this good.
> The K3, several of the Flex radios, the Eagle, the TS-990, and of
> course the Hilberling are all good radios needing no pre-selector.
>
> Nearly 15 years ago I made some recordings of a Jupiter with and
> without the pre-selector and sent it to Ten-Tec.
> After reviewing them, Jack commented that he had always heard condx
> were worse here in Europe, but never knew they were of that magnitude.
> As a result, he immediately added provision for a pre-selector to the
> Omni VII design, which was still on the drawing board.
>
> The Argonaut V was pretty much a disaster here.
> The author of the QRP section of a local magazine described its
> receiver as pretty much useless on 40m.
> Sales here were pathetic.
> Yet in the states it is a fine radio.
>
> The Paragon with its upward conversion will have a blanket of noise
> (wave
> salad) across the 40m band, when used with a good antenna.
>
> The good news is, if you live in the states, you will never experience
this.
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt am Main)
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Wade
> Staggs
> Sent: Thursday, October 02, 2014 7:49 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] Modern version of the Tec Tec Corsair - please
> Ten Tec!
>
> *Hello Rick,*
> * Over the last several years, I have found real
> respect for your Facts and Opinion. Could you please expand and
> explain. I know that in Europe, you have a whole different bunch of
> problems from Broadcast Stations but, can you explain just what
> feature... IF, Selectivity or other, where the Paragon falls short?
> Would a Band Pass filter help? I call 4 to 7 HF Nets a week on 80/75
> Meters. With the RF Gain backed off (( like we ran our Corsair )) and
> the 1.8 KHZ Filter selected, even with Loads of QRM, we can still hear
> stations that others miss. Even to the point that other NCS stations
> always ask me to relay weak signals into the Net. When they know I am
> on frequency that is. Of course they are running mostly KenYaeCom
> Rigs. My antenna is nothing special. 126 feet of Flat Top Dipole with
> Windows ( 450 ohm ) Line into the tuner. A real Cloud Burner (( NVIS
> )) at about 30 feet high. While I have your attention Rick, Thanks for
> answering my many questions that we would have ask, if others had not
> ask first. Do you wear a Solid Blue Shirt with a Big Yellow S on the
> front?? Do you get your Cape caught in Car Doors? Well. I believe that
> you do. Do they still have Phone Booths for the quick wardrobe changes
> in Germany? *
>
> * Thanks Rick 73 from
> Wade/KJ4WS*
>
> On Thu, Oct 2, 2014 at 11:34 AM, Rick - DJ0IP / NJ0IP <Rick@dj0ip.de>
wrote:
>
>> Come to Europe Wade, you'll learn the difference (in favor of the
>> Corsairs).
>> Upward conversion struggles here.
>>
>> 73 - Rick, DJ0IP
>> (Nr. Frankfurt am Main)
>>
>>
>> -----Original Message-----
>> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Wade
>> Staggs
>> Sent: Thursday, October 02, 2014 6:15 PM
>> To: Discussion of Ten-Tec Equipment
>> Subject: Re: [TenTec] Modern version of the Tec Tec Corsair - please
>> Ten Tec!
>>
>> *Good Morning,*
>> * While the Corsair and Corsair II are fine
>> radio's. If you really want to split hairs, my Paragon ( 585 ) has
>> everything they have, plus very accurate ( no drift at all )
>> frequency control. Don't believe me? Just find someone who owns one
>> and sit down in front of the rig. Now engage the 20 Db. pad and turn
>> the RF Gain back just a little bit. ( this is on the low bands ) It
>> just seems like a different world. And while I am posting. Why did
>> the Paragon and Paragon II have relatively short production runs? I
>> know about the Dreaded ... PLL Out of Lock ... problem with the 585
>> but once fixed, they are such Great Radio's.
>> Mine was acquired while broken but a thorough re-work of the Major
>> and Minor Loop Boards has turned it into a real Keeper. Almost 6
>> years now with no failures or issues of any kind. Although about 6
>> months back we did replace all capacitors in the PA enclosure. So, in
>> summary, has anyone used a Paragon ( 585 ) lately ? ? ? And who wants
>> to trade their broken one for something else? All input about the
>> Paragons receiver appreciated.........
>> The Transmitter is Awesome also.*
>>
>> *
>> 73 from Wade/KJ4WS*
>>
>>
>> On Thu, Oct 2, 2014 at 6:42 AM, Rick - DJ0IP / NJ0IP <Rick@dj0ip.de>
>> wrote:
>>
>>> As nice as its audio was, the KWM-2 would not be very good with
>>> today's crowded bands.
>>> The famous "Collins mechanical filter" was not really very good by
>>> today's standards.
>>> A 4-pole crystal filter on 455 kHz is as good or better and of
>>> course you can buy 6 or 8 pole filters now.
>>> And the DSP filters on lower frequencies are even better, sharper,
>>> and have steeper skirts.
>>>
>>> As long as we're dreaming, I wish I had 1960's band conditions again!
>>>
>>> All things considered, it's hard to beat the Corsair with its
>>> combination of good audio and good crystal filters.
>>> Newer radios have better filters but worse audio.
>>>
>>> For my money, the best compromise is the Eagle.
>>>
>>> 73 - Rick, DJ0IP
>>> (Nr. Frankfurt am Main)
>>>
>>>
>>> -----Original Message-----
>>> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of
>>> Martin Sole
>>> (HS0ZED)
>>> Sent: Thursday, October 02, 2014 11:37 AM
>>> To: Discussion of Ten-Tec Equipment
>>> Subject: Re: [TenTec] Modern version of the Tec Tec Corsair - please
>>> Ten Tec!
>>>
>>> I've long liked the analogue radio sound. So far my all time fave,
>>> just for the audio, is a KWM2 with that big 6x4 speaker, something
>>> about that warm sound seems magical. Next up from my current radios
>>> would be my Omni V. Not sure how that might differ from the Corsair
>>> but whilst generally pleasant it's not in the KWM2 league. Then the
>>> Orion 565 and Elecraft K3, bit of a mixed bag these two as they are
>>> both very variable but I've not yet been able to recreate the
>>> analogue sound. I might need to experiment with amplifiers right at
>>> the point the signal becomes analogue. A god analogue audio amp with
>>> LTP input and complementary pair output in discrete silicon feeding
>>> a big speaker,
>> might sound very different.
>>> The TS940 had good audio too but for me about the same as the Omni V
>>>
>>> Martin, HS0ZED
>>>
>>>
>>> On 02/10/2014 12:03, Barry N1EU wrote:
>>>> On Wed, Oct 1, 2014 at 5:12 PM, John Farler <k4avx1@windstream.net>
>>> wrote:
>>>>> I have a Corsair II with the DDS VFO, which works nicely. I think
>>>>> it's a single conversion though.
>>>> Normally it converts to 9MHz, then to 6.3MHz, and then back to
>>>> 9MHz, unless you bypass the 6.3MHz PBT i.f. which can be done
>>>> fairly easily but you lose PBT and narrow filters and don't gain much.
>>>>
>>>> I agree on the CAT comment. I always dreamed of adding a CAT port
>>>> to the DDS cpu firmware.
>>>>
>>>> 73, Barry N1EU
>>>> _______________________________________________
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>>>> TenTec@contesting.com
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>>>>
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