Search found 662 matches

by glovisol
Wed Sep 05, 2018 1:21 pm
Forum: General
Topic: REMOTING RSP VIA USB - PROBLEM SOLVED
Replies: 2
Views: 2657

REMOTING RSP VIA USB - PROBLEM SOLVED

Today I received an USB2.0 repeater cable manufactured & sold by LogiLink Germany with a length of 10 m. On Ebay I paid EUR 11.00 for the cable + EUr 7.00 for express courier shipment. Connected the cable between the PC USB output and the 5 m USB cable coming from my RSPduo. Switched RSPdu on: the s...
by glovisol
Tue Sep 04, 2018 6:33 am
Forum: General
Topic: HF weak signal reception in presence of noise
Replies: 10
Views: 5011

Re: HF weak signal reception in presence of noise

Another example with AGC + IF AGC in manual and at minimum with perfect copy of S5 signal in S5 noise.
by glovisol
Mon Sep 03, 2018 9:55 am
Forum: General
Topic: SDRuno S-Meter = S5 With No Antenna
Replies: 13
Views: 6605

Re: SDRuno S-Meter = S5 With No Antenna

Hi Murphy, As an old timer like yourself, in the fifties & sixties I used different receivers, amongst them the Racal RA17 and the Collins 75A4, at the time judged the best. - With AM reception one kept AGC ON and audio level was adjusted with the volume control. - With SSB reception one kept AGC OF...
by glovisol
Sun Sep 02, 2018 12:56 pm
Forum: General
Topic: HF weak signal reception in presence of noise
Replies: 10
Views: 5011

Re: HF weak signal reception in presence of noise

To reiterate and summarise after a lot of listening, this "noise advantage" is very marked as long as the antenna noise is high, in the order of -100 to -110 dBm and becomes less and less significant for antenna noise at or below -125 to -130 dBm. With my setup, Beverage antenna on the 80 & 40 m ban...
by glovisol
Sun Sep 02, 2018 5:55 am
Forum: General
Topic: HF weak signal reception in presence of noise
Replies: 10
Views: 5011

Re: HF weak signal reception in presence of noise

Hi g4enz, thanks for the suggestion: the fact is that the best improvement is gained with threshold at minimum, which equates to AGC OFF....In effect with AGC OFF, the AGC cursor you mention still controls the RF gain : by using this control as a manual volume gain you even better optimise noise rej...
by glovisol
Sun Sep 02, 2018 5:44 am
Forum: General
Topic: HF weak signal reception in presence of noise
Replies: 10
Views: 5011

Re: HF weak signal reception in presence of noise

The explanation of the "low noise" effect should be as follows: 1) With AGC "OFF" and no antenna the system sets for minimum gain: e.g. the noise level internally generated . 2) When you re-connect the antenna the gain stays at the previous level (internally generated noise) and the weak signal is a...
by glovisol
Sat Sep 01, 2018 7:04 pm
Forum: General
Topic: HF weak signal reception in presence of noise
Replies: 10
Views: 5011

Re: HF weak signal reception in presence of noise

ANOTHER TRICK - UNKNOWN BUT UNBELIVABLE PHENOMENON IN HF BANDS (ONLY TESTED 80 & 40 M) 1) Turn receiver ON and make sure AGC is OFF. 2) Disconnect antenna terminals. 3) Reconnect antenna. 4) You will see the signals on the display and hear them perfectly, BUT THE BACKGROUND NOISE IN YOUR AUDIO WILL ...
by glovisol
Sat Sep 01, 2018 6:26 pm
Forum: General
Topic: HF weak signal reception in presence of noise
Replies: 10
Views: 5011

HF weak signal reception in presence of noise

Even if I live in the country far from big noise sources, the 80 m band represents a problem with average noise levels of -100/105 dBm throughout day & night. Weak signal reception in presence of fading can be improved with a simple old timer's trick. Set RF gain mid-way (so to make sure you do not ...
by glovisol
Fri Aug 31, 2018 3:07 pm
Forum: General
Topic: Remote RSP via USB/CAT5
Replies: 27
Views: 9944

Re: Remote RSP via USB/CAT5

Hi Jukka, Seriously, if one does have heavy RFI in location X - according to me, there is no USB, no (antenna) coaxial-based solution even how extended to get RFI-levels acceptably low. Before getting on with this discussion, you should define what you mean by "acceptably low" and also define what t...
by glovisol
Thu Aug 30, 2018 4:19 pm
Forum: General
Topic: Remote RSP via USB/CAT5
Replies: 27
Views: 9944

Re: Remote RSP via USB/CAT5

Hi Fresnoboy,

This could be a very valuable idea, but first you must check the QRM locally generated by the small PC board and/or if it can be esily shielded. If this board radiates to the RSP receiver we are back to square one.

glovisol