Home |
Search |
Today's Posts |
#2
![]() |
|||
|
|||
![]()
Most of the newer stuff uses glass epoxy circuit boards and SMD technology,
so actually, it isn't bad. Most of the older stuff did not. I had an Icom 735, and although it was a good unit, the Kenwood 570 has a better overall receiver. The 735 uses a dual JFET balanced mixer, while the 570 uses the same type of quad JFET mixer that is used in the Yaesu FT1000 series and the Racal 6790. The quad mixer has a theoretical IP3 of +30dBm if implemented properly, while the dual JFET design is typically in the +15 to +20dBM range. Mind you, this isn't bad. Nothing out of the old portable radio series comes to the Grundig 210 (1971), the Grundig 600 and 650s (early 80s), and to a lesser extent, the Zenith Royal 7000, not to be confused with the later R7000, which is also not too bad of a receiver. The full audio response of those older Grundig receivers has to be heard to be believed. I gave my Grundig 210, also known as the TR-6001 to my wife. She still likes to play with it. The Grundig Satellit 700 seems to command high prices, but it is relatively deaf when compared to the older Grundig units. Probably, the most advanced Grundig radios were the Satellit 600 and the Satellit 650. These were of an upconversion design using a glass epoxy board for the main receiver board. Real optical encoders were used for the main tuning control, as well as a tracking preselector for the front end. These were the last Satellit models that used the tracking preselector, as well as the Variometer driven RF stage for the LW/MW/MB ranges. They also used a two way acoustic suspension speaker system. Another receiver that comes to mind is the Philips D2999. LW/MW performance was just as good the the Grundig Satellit receivers. The problem is finding a unit that doesn't have worn out pushbutton band select switches. It is difficult to get at those switches in order to clean them. The Sony 6800W, Orange version is a good performer, if you can find one that is working properly. This is also a very difficult receiver to dismantle, making it difficult to service. Some people prefer the version with the white lettering with its shallower skirt selectivity. Both of the receivers are using a Murata "H" bandwidth filter, except the Orange version uses a 6-element CFWS-455H while the White version uses a 4-element CFU-455H in the 455kHz I.F. strip. The 6-element version has potentially better ultimate rejection, but because the 2nd mixer doesn't have a crystal roofing filter ahead of it the close-in IP3 is relatively poor. Still, it is a fun receiver to play with. If I ever find a clean sample at a reasonable price, I will pick it up again. There is one on eBay right now, but that "as is" reference that the seller uses is pretty scary, especially when this receiver is known to have problems with the sythesizer going out of lock. The newer Chinese portables aren't bad..............the limiting factor with these units is using only a 2-pole roofing filter at the 1st I.F. This gives a maximum 2nd I.F. rejection ratio in the 45dB range. You can see the manifestation of this problem when you hear the (2 X 455kHz) images of the 6MHz band when you tune 910KHz below the 49M band. Since this is a 2nd I.F. rejection problem, it will occur throughout the whole tuning range. An outboard tunable RF preselector will give you better rejection of this problem. I did get to play with Prototype 4 or 5 of the E5 when it first came out. Too bad they didn't stick with the blue LED backlight for the display. It looked much nicer than that washed out display that they are using now. Now, the E5 was a better performer than the Sony 7600, although the 7600 isn't a slouch either. There is also the Panasonic RF-2200. This is a pretty good receiver, but it definitely doesn't have the MW performance of some of the better portables. Image rejection isn't the best either, because of its 2MHz 1st I.F. This in itself isn't bad, but with this type of design you really need 3-gang tuning to get that extra stage of image rejection. Anybody who has used this receiver will notice those images that are offset 4MHz from the original signal. Still, it is nice to have that "Collins" looking tuning dial. It was a pretty good deal at the original 140 price tag. It also had a great FM section with super selectivity. What is my favorite portable? My Sony SW-1, although that only gets about 10 minutes of use every month or so. If it had a larger loopstick antenna, it would be a great receiver. When coupled with the Radio Shack tuned loop antenna, it is as good as the best. SW performance is also very good. Even with the short whip antenna, it is possible to hear atmospheric noise overriding internal noise up at 29MHz. This unit also uses glass epoxy boards. The reason that I mention glass epoxy boards is because this material has better dimensional stability than the old phenolic boards. Because of this, you don't run into intermittent connections the way that you do with the phenolic material. The Yaesu FRG-100 uses phenolic boards, but it is such a nice receiver that I have kept mine, in spite of this fact. I keep this receiver in a controlled climate, so it shouldn't have any problems. One receiver that I have coming from England is a Lo-Kata ADF receiver. It looks like a good design, but the Christmas mail has slowed down progress of this shipment. Cosmetic design is similar to the Lowe HF-150, only in giant size. I don't know too much about it yet; I may end up having to break it open and repair it. Whenever I do get the chance to play with any of my receivers, it is my JRC NRD-91. You don't see too many of those units around, because they are still sitting on high seas ships, along with the NRD-92, NRD-93, some of the Sailor brand receivers, and who knows what else? Pete "snow" wrote in message news:BCZjh.16745$sz5.3423@trndny03... I have tried out several SW radios over my 15 years in the hobby. I was thinking about this recently. I have owned the Radio Shack DX-440, Sony SW100, Grundig YB 400 and 305, Degen 1103 and also a Ham Radio Icom 735. The best portable by far for sound, quality of contruction and sensitivity was the DX-440. The Degen 1103 is a fine small portable, but it still is not in the same league as the DX-440. The Grundig YB 400 is also an ok radio, though the YB 305 (no SSB) beat it out for sensitivity. The Sony SW100 was VERY small......still no DX machine. Finally, the Icom 735 though a ham radio was EXCELLANT as a receiver, but it was a $1000 radio new back in the 80's and early 90's, so one would expect good performance. I come to conclusion that though today's SW radios do have some great buys like the Degen 1103......the older radios I have owned like the DX-440 and Icom 735 easily outperformed the newer stuff. Actually I can't think of a radio under $200 that I would want now.....would consider a used 440 or Sangean 803a first. Though I never owned one, I have heard the discontinued Sony 2010 was also superb. Is the newer stuff not as good as far as quality of construction and DX ability goes? Interesting to hear what others think. |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Used portable shortwave radios available | Equipment | |||
Modified 1/8" Mono Plug for a 'portable' Radio's Ground Connection | Shortwave | |||
What the Eton E1 Rado is NOT ! -=V=- What It "IS" and What Not to Expect | Shortwave | |||
Comparison of six portable radios | Broadcasting | |||
Motorola MX-350 Portable Radios $ 10.00 Ea | Swap |