Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]() "Michael Black" wrote in message ... Rick ) writes: Well, I am beginning to have some doubts about the likelihood of finding an excellent-quality Hammarlund HQ-180 at a price I can afford. Certainly I am going to keep looking, but meanwhile I guess I need to come up with a few alternatives that I can "settle" for if, as seems likely, the HQ-180's have priced themselves out of my reach. I need something that is all tubes, and works well on SSB. I plan to use it mostly on CW but I need decent SSB performance. AM is relatively less important (it should work on AM but doesn't need to be a spectacular performer). It does need to be general coverage 500 KHz to 30 MHz. R390's and 51J4's would be good (but of course, more expensive than the HQ-180) but none comes with a product detector and so performance on SSB is likely to be marginal at best, right? This is mostly a myth. I had an SP-600 for years, and never had problems receiving SSB. You just turn down the RF gain, turn up the audio gain to compensate, turn on the BFO and tune away. The issues of using such receivers for SSB date from the very early days, when people didn't understand how to do it, and so they were disappointed. Obviously, some cheap receivers did have problems, because even with the gain turned way down, the BFO wasn't strong enough. But that's not likely the case for the better receivers. The limitations would be in whether the dial allows for fine enough tuning (which will likely be fine in those receivers) or lack of selectivity (which won't be a factor with those receivers, and doesn't actually affect SSB reception, just affects how much other clutter you do receive). Having a product detector did make it easier to tune in SSB signals, making the process less cumbersome. Michael VE2BVW Many receivers without product detectors will do OK on SSB but the problem is having to run at low RF gain and having no AVC. My SP-600 does OK but I got better results with my old BC-779 (SP-200 Super Pro) because the BFO injection is isolated from the AVC and is greater. I don't know why Hammarlund did not adapt this method to the SP-600 but it is only one of several puzzles about the design. BTW, I have never understood the need for adjustable BFO injection on most SP-600 models. The books suggest running it at maximum but that results in tube overheating of the buffer and some oscillator pulling. I set mine so that the tube bias is "normal" for maximum amplification, 1 volt measured at the cathode with the BFO off. The JXZ-17, which has fixed injection, runs at this bias level. There are many approaches to building an SSB adaptor. In many cases they can be made to be plug-in with no modification to the receiver. A great many designs were published in QST and CQ magazines beginning in the mid 1950s when SSB was becoming popular. -- --- Richard Knoppow Los Angeles, CA, USA -- Posted via a free Usenet account from http://www.teranews.com |
#2
![]() |
|||
|
|||
![]() "Rick" wrote in message news ![]() Well, I am beginning to have some doubts about the likelihood of finding an excellent-quality Hammarlund HQ-180 at a price I can afford. Any suggestions, places where I should start looking? Drake R-4 with the outboard synthesizer for general coverage. Pete |
#3
![]() |
|||
|
|||
![]()
Rick wrote:
I need something that is all tubes, and works well on SSB. I plan to use it mostly on CW but I need decent SSB performance. AM is relatively less important (it should work on AM but doesn't need to be a spectacular performer). It does need to be general coverage 500 KHz to 30 MHz. Hallicrafters SX-122 or SX-122A. Nice 50 KHz last IF with selectable sideband and appropriate AGC. OTOH, It's not that hard to do single-signal CW and SSB with an R-390/391/392 on the 2 KHz bandwidth setting. -- P Joshua Rovero KK1D Boatanchor radio afficionado, ABC #9277 1985 R80RT Oceanographer, Meteorologist, Curmudgeon at Large http://www.roveroresearch.com |
#4
![]() |
|||
|
|||
![]()
On Mar 24, 8:01 pm, Rick wrote:
Well, I am beginning to have some doubts about the likelihood of finding an excellent-quality Hammarlund HQ-180 at a price I can afford. Certainly I am going to keep looking, but meanwhile I guess I need to come up with a few alternatives that I can "settle" for if, as seems likely, the HQ-180's have priced themselves out of my reach. I need something that is all tubes, and works well on SSB. I plan to use it mostly on CW but I need decent SSB performance. AM is relatively less important (it should work on AM but doesn't need to be a spectacular performer). It does need to be general coverage 500 KHz to 30 MHz. R390's and 51J4's would be good (but of course, more expensive than the HQ-180) but none comes with a product detector and so performance on SSB is likely to be marginal at best, right? I have looked at a few Hallicrafters SX-100's (that is to say, looked at their pictures on eBay... haven't actually seen one up close in at least 30 years). How does that model and other comparable models from Hallicrafters and National stack up? Did Heathkit ever make a general-coverage communications receiver that was worthy of the name "communications receiver"? I know they had one, I think the model was AR-3. I had one when I was a kid and it wasn't much. Everything else I've seen from them seems to be ham bands only, and mostly 80-10 (no 160). Any suggestions, places where I should start looking? I would love to have an HQ-180 also but they are just too pricey. I did find a nice HQ-170 on Ebay and restored it. The HQ-170 is not general coverage but I really like mine for general boat anchor Ham use. You can check out my HQ-170 and Ranger on my Flickr site. http://www.flickr.com/photos/wb5kcm/...7594523189590/ It's not the greatest AM fidelity wise receiver due to the narrow IF bandwidth but still does a nice job. You can pick up a nice HQ-170 at hamfests for around $100 to $200 depending how pretty it is. 73, Randy |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
FA: $10> GENERAL RADIO TYPE No. 1803-B VACUUM TUBE VOLTMETER NR | Equipment | |||
FA: Amplex Model "C" Tube Type Radio - Antique Type - Quite Old | Swap | |||
FA=GENERAL RADIO type 722-DS9 VARIABLE CAP-NEW are $11K? | Equipment | |||
General Coverage Attic Antenna Suggestions ? | Shortwave | |||
General Coverage Attic Antenna Suggestions ? | Antenna |