We present maps of the sky at intermediate angular resolution (5 deg) of the declination range 35.0-45.0 deg obtained with the Tenerife cosmic microwave background (CMB) experiments using data up until 1992. The data were taken with bean-switching radiometers operating at 10.4 and 14.9 GHz. Right ascension scans were made at 2.5 deg declination intervals centered on decl. +40 deg covering 3500 sq deg of sky. The observations have been compared with known point sources and estimates of Galactic emission as a consistency check on the integrity of the data set. After subtraction of radio sources, the section of our data from R.A. 161 deg to 230 deg has been analyzed using a likelihood method with a Gaussian autocorrelation function. At 10.4 and 14.9 GHz we find evidence for fluctuations with intrinsic amplitudes of square root C0 = 41(+26, -30) and 66(+29, -22) micro-K (68% confidence limits), respectively, on a coherence scale of 4 deg. These levels are consistent with the expected rms sky signal from the COBE differential microwave radiometer first-year resuts and with the CMB signal detected at 14.9 and 33 GHz in the decl. = +40 deg strip by Hancock et al. (1994). Our results at 10.4 GHz set strong upper limits on the Galactic contamination at 14.9 GHz, suggesting that the signal found at the latter frequency is probably dominated by cosmological fluctuations.